Simba Sleep Hybrid Ultra Mattress Review

Sizes and trial period

• Single to Super King, but no EU variants
• 200-night trial period

The Simba Sleep Hybrid Ultra is available in four configurations – Single, Double, King, and Super King – though it misses the EU Double and EU Queen sizes found in other Simba mattresses. 

Buying a mattress you can’t test beforehand can be a worry, but Simba tries to alleviate it with a 200-night trial period, with a free collection and complete refund at any point during this period. And, if you do decide to stick with it long-term, Simba offers a competitive 10-year guarantee to protect against defects. 

Design and layers

• 11 layers deep
• Hybrid spring and foam design
• Removable, washable top cover

As with most modern mattresses – especially those ordered online – the Simba Sleep Hybrid Ultra arrived vacuum sealed in plastic, inside a rather large cardboard box. It sounds weird, but it’s my preferred way to receive them, making it much easier to move into my upstairs bedroom than my previous, unwrapped, mattress. 

The unboxing process was pretty simple: I just cut along a line to release the pressure and allowed the mattress to unfurl – but be prepared for it to spring out. Placing it at the foot of the bed before cutting makes the process much easier, especially with the king-size sample I was sent. It’s recommended that two people take on the task, but I managed alone just fine. 

Once unfurled, you’ll need to leave the Hybrid Ultra for around six hours to expand into its fully shaped form – again, pretty standard for a vacuum-sealed mattress. Luckily, my sample arrived in the morning, and I unpacked it at lunch, giving it ample time to fluff up before I got into bed that night. 

It was that evening that I realised just how thick and luxurious the Hybrid Ultra was; measuring 34cm thick, it’s much thicker than the 28cm-deep Simba Hybrid Pro – the next step down in Simba’s mattress collection. It does mean you’ll need to make sure your fitted sheets are deep enough to reach the bottom of the mattress; a few of my existing sheets weren’t quite deep enough and kept popping out. 

That thickness also means your overall bed height may increase, depending on the mattress you’re coming from, but I think it adds to the luxurious feel. It’s nice to be farther from the floor when climbing into bed, in my opinion. 

As with other Simba mattresses, the Hybrid Ultra comes with a soft, breathable top cover with diamond patterning that the company claims works with the springs and fillings to better accommodate you. 

That’s accompanied by a zip that runs along the sides of the mattress, allowing you to remove the top cover for machine washing – another benefit compared to the Pro, which, despite also featuring zips, isn’t designed for home removal. 

It does negate the need for a mattress protector, but with a mattress as premium as this, I’d still recommend splashing out on one for those accidental spills. 

So what is it that makes the Hybrid Ultra, y’know, Ultra? It comes down to the layers within the mattress. While the standard Simba Hybrid offers five layers and the Hybrid Pro offers seven layers, the Ultra offers a whopping 11 layers to help deliver a truly top-end snoozing experience.

That starts with the aforementioned top cover, which uses Simba’s Stratos tech to help keep you cool all night. Below that, there’s a layer of a blend of wool, bamboo, charcoal and kapok, again designed to help keep you cool and the mattress breathable.

Continuing the journey down, you’ll next hit not one but two layers of the company’s Simbatex foam, which again aids with airflow and cooling, as well as adding some cushioning and elasticity to the mattress.

Then comes Simba’s PureLift layer, a blend of latex and coconut that further boosts elasticity and provides spring-like support.

The actual springs are found beneath that layer, with not one but two layers of Aerocoil micro springs, split into 13 zones across the mattress to better distribute weight and support specific areas of the body, like the hips and shoulders. 

Next comes a stabilising core foam layer to provide additional structural support, as well as more of that all-important airflow.

Because two layers of springs weren’t enough, there’s another layer of 2500 carbon steel springs to further boost overall support, with an additional 1000 tempered steel barrel springs beneath that help keep the mattress firm right up to the edges.

Finally, there’s a foam base that adds extra depth and provides a final layer of support. 

With such a specific, complex layering system, it shouldn’t come as much of a surprise that the Hybrid Ultra isn’t designed to be flipped. 

Instead, Simba says you should rotate the mattress once a month for the first three months, then every three to six months going forward, to help maintain the mattress’s overall quality and avoid dips or sagging. 

The built-in handles on the sides of the mattress make this job relatively easy, but larger mattresses – like my king-size sample – may require two people. 

Comfort and support

• Remains firm, right up to the edges
• Excellent support in most positions
• Not the best at absorbing movement

To better assess just how supportive the Hybrid Ultra is – Simba simply claims it’s a medium/firm mattress – I took various measurements at key points to see how far I sank into it. 

Coming from an exceptionally soft Tempur memory foam mattress, the difference was immediate. The Hybrid Ultra feels much more supportive, especially towards the edges where my previous mattress would get a little soft, and that’s largely backed up by the measurements I took.

Sitting on the edge of the mattress, I measured a drop of 8cm, compared to 14cm of my old mattress. This may not sound like much, but it made a massive difference in actual use, meaning I could get much closer to the edge of the bed without feeling like I was slipping off. 

Next, I sat cross-legged in the middle of the mattress – my preferred positioning for reading my Kindle before I doze off – and sank 5cm, compared to 13cm from my old Tempur mattress. Again, you really feel that support, making it not just more comfortable to sit upright on, but to manoeuvre yourself into a comfortable position. 

It was then time to test the all-important sleeping positions. Of course, everyone sleeps a little differently, but I tried the three most common positions: back, side and front. 

On my back, I measured a dip of 4cm at my hips and a shallower dip of 2cm at the shoulders, which helps keep the spine aligned during sleep. In comparison, my old Tempur mattress dipped to 13cm and 7cm respectively. 

Rolling over to my side, I measured a similar dip of 6cm and 4cm at the hips and shoulders, while sleeping on my front showed a dip at my stomach of 7cm. All of this pretty much aligns with my anecdotal experience of finding the mattress firm but not uncomfortable. The level of support is excellent regardless of how you sleep, though it took me a couple of weeks to adjust to it after using my softer Tempur mattress for five years. 

Those who prefer a soft, pillow-like mattress likely won’t get on with the Hybrid Ultra though; my previous mattress felt like it was enveloping me as I lay down, while the Hybrid Ultra feels more like a gentle hug. 

The one downside to a hybrid design like that of the Hybrid Ultra is that it doesn’t do as good a job at suppressing movement as a pure memory foam alternative. 

To help evaluate how well the mattress absorbs nighttime movement, I used an accelerometer placed in the position of a second sleeper. The idea is simple; the more movement the accelerometer picked up, the bigger the spikes in the graphs. As you can see, the Hybrid Ultra doesn’t do a terrible job, but the Tempur mattress is better in this regard.

Getting into bed, you can see a much bigger spike when compared to my old mattress, which registered barely any movement on our accelerometer. 

That trend continues when moving in bed; the Hybrid Ultra does a fine job, but it can’t quite compete with the full memory foam alternative. 

That aligns, at least anecdotally, with what my partner and I have experienced over the past few months, noticing movements – especially getting in and out of bed – much more often than before. It’s not a terribly wobbly mattress or anything, far from it, but it’s not quite as movement-muting as some might like.  

Heat

• Comfortable to sleep on
• Never gets too hot
• Dissipates heat quickly

Memory foam mattresses have a bit of a reputation for being hot to sleep on, especially in the warmer summer months. While I haven’t had the chance to test it during the summer months just yet, I haven’t felt too warm in bed for the past few months – and it’s mainly down to the Hybrid Ultra’s layering tech, helping keep airflow moving throughout the mattress.

To test just how quickly the mattress cools down after lying in the same spot, I laid on my back for 10 minutes, and then used a thermal camera to evaluate just how long it’d take to dissipate. 

The first shot was taken immediately after I got up, and of course, it’s pretty warm – you can tell not only by my hot outline but how dark the surrounding room looks in comparison. However, within a few minutes, the body outline temperature was much closer to the bed around it. It’s still visible, yes, but nowhere near as hot – especially compared to my old Tempur mattress.

Compared to the Simba mattress, my old Tempur mattress retained much more heat – seen not only by the more detailed outline but the way the cold purple-ish hue remains around the outline, even after a few minutes, showing a dramatic difference in temperature. 

Should you buy it?