Which is better for a bunk bed?

The Mainstays. Its 6 in height and firm coil support suit bunk and trundle frames, and it costs less. Check your bunk's weight limit before buying.

Which is better for side sleepers?

The Zinus. Memory foam cushions hips and shoulders, which helps side sleepers on a thin mattress. The Mainstays is firm and may feel hard at the shoulder.

Neither is a long-life mattress at this price. The Mainstays coils can lose firmness and squeak; the Zinus foam softens and develops body impressions. Expect a few years of regular use from either.

Is the Zinus worth the extra $8?

Yes if you want foam comfort or a size other than Twin. No if you want a firm feel for a bunk or guest bed, where the Mainstays saves money.

Do both come rolled in a box?

The Mainstays is sold as a mattress-in-a-box. The Zinus is also a bed-in-a-box foam mattress. Both need time to expand after unboxing.

Which is better for a heavy adult?

Neither 6 in model is built for heavy adults. A thicker Zinus, such as the 10 or 12 in, gives more foam under weight and is the better pick of the two.

Mainstays 6 in Twin Tight Top Innerspring Mattress with Gel Foam vs Zinus 6 Inch Twin Green Tea Memory Foam

Buy the Mainstays if you want a firm innerspring feel and the lowest price: $88.88 at Walmart as of November 4, 2026. Buy the Zinus if you want memory foam that cradles pressure points and more size and thickness options; it starts at $96.99 at Newegg.com as of November 4, 2026. The gap is about $8, so pick by feel, not by price.

Today the Mainstays 6 in Twin Tight Top Innerspring Mattress with Gel Foam costs $8.11 less at its best price.

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