Simba vs Otty: Which Should You Buy?

This is the most instructive comparison on the site, because it shows what the word hybrid actually covers.

The Simba Hybrid uses Aerocoils: 25 millimetre micro-springs in the comfort layer, sitting on a foam base.

The Otty Original Hybrid has a 16 centimetre pocket spring core.

Both are legitimately called hybrids. One has springs near the surface doing comfort work over foam that does the supporting; the other is supported by springs through its full depth.

That single difference drives almost everything below: temperature, durability, how each behaves under a heavier body, and what happens in year eight.

The specification that decides it

The second row is the comparison. A 25 millimetre comfort layer cannot support a body; it shapes how the first inch feels. Everything below it on the Simba is foam, and everything below the surface on the Otty is steel.

This is not a criticism of micro-springs, which do a real job: they are more responsive than foam at the surface and they let some air move. It is a caution about the word hybrid, which covers both constructions and distinguishes neither.

Scored side by side

Why the temperature gap is this wide

Heat leaves a mattress when air moves through it. That is structural rather than chemical, and no treatment, gel or fabric substitutes for it.

A 16 centimetre spring core is a large volume of open space with air circulating through it continuously. A 25 millimetre micro-spring layer over solid foam is a thin band of open space sitting on a layer that has almost none.

So the Simba is cooler than an all-foam mattress such as the Emma Original, and not in the same category as the Otty.

One thing that undoes either: a foam topper on top, or a cheap plastic-backed protector, both of which seal off the airflow you paid for. If a hybrid needs softening, use micro-spring, spacer mesh, latex or wool.

Body weight changes the answer

Firmness ratings are set for roughly ten to fifteen stone. Under that, a rated 7 feels firmer than 7. Over it, the same mattress feels softer and supports less than the number implies, and a foam base is where that shows first.

What happens in year eight

This is where the constructions separate most and where neither brand helps you.

Foam fails by compression set: cell walls gradually collapse, so the mattress loses height and support while looking identical. Density is what predicts how long that takes, decent comfort layers running 48 to 72 kilograms per cubic metre, and neither Simba nor Otty publishes it. Ergoflex is the only brand on this site that does.

Steel does not age that way. A pocket spring unit that is not abused holds its geometry for a decade and more, which is why a spring-supported mattress tends to outlast a foam-supported one at the same price.

Both depend on the base. Slats more than about 7.5 centimetres apart cause sagging into the gaps and void most guarantees, which means the frame creates the fault and then disqualifies the claim.

Trial and price

Simba's 200 nights against Otty's 100. Both are enough, because firmness cannot be judged in a week and a fortnight is the minimum before a new mattress tells you anything useful.

Both discount heavily and continuously, so the crossed-out price is a statement about their own pricing. The CMA secured undertakings from Simba in August 2024 requiring that was and now prices reflect genuine previous selling prices.

The bargain worth knowing in Simba's range: a refurbished Hybrid Ultra has listed at around £699 against £1,749 new, which is 34cm and 7,300 springs and better value than anything else Simba sells.

Who should buy which

Buy the Otty if you sleep hot, you are of average build or heavier, you want the mattress to last, or you want the most construction per pound. It wins on five of seven criteria.

Buy the Simba if you are lighter, you want a slightly softer more conforming surface, or you want the longer trial while you work out what firmness suits you.

Buy neither if you want maximum specification for the money, which points at Origin, or you and your partner disagree about firmness, which points at dual firmness.

Where to go next

How this list is made, and who made it

Who writes this. Kyle Klinkradt has worked in the mattress and bedding industry for over ten years across retail, distribution and brand partnerships, and has handled, sold or assessed products from every major UK bed-in-a-box brand. Every review on this site is written by one person, so the scores mean the same thing from page to page.

What the assessment is. Construction specifications against what they physically do: spring height and where in the mattress it sits, spring count for the size, gauge, whether the base is sprung or foam, foam density where it is published, comfort layer depth and material. Then the commercial terms that decide what you are actually buying: trial against returns policy, guarantee length against the company's UK trading history at Companies House, and the regulatory record.

What it is not. This is not a laboratory. I do not publish pressure-mapping data or claim to have slept eight years on every mattress here, because nobody has and pages that imply otherwise are not telling you the truth. Where a judgement rests on construction rather than long-term use, the review says so.

What gets a product removed. Leaving the UK market, a specification change that makes the review inaccurate, or a corrected fact. Brands that have withdrawn are kept on the site with the score removed rather than quietly deleted, because people still search for them.

See editorial independence, corrections and the author page.

How this comparison is made

Both products are scored on the same criteria used across this site: support, pressure relief, motion isolation, edge support, temperature, durability and value. The scores in the table are the ones on each product's own review page, and they do not change to suit a comparison.

Where a brand publishes a specification, it is quoted. Where it does not, that is stated rather than estimated, because an absent specification is itself information: foam density and spring count for your own size are the two most commonly withheld.

Prices move constantly in this category and both brands discount heavily, so cash prices are given as a guide and the comparison rests on construction rather than on a percentage off.