In 2023, I reviewed the ZenBivy Core sleep system and said I liked it so much, I expected it would replace my other sleeping bags for the foreseeable future. Welp, in early 2024, ZenBivy asked if I’d like to review their updated Ultralight system. Why not? And a few weeks later, a new down-filled sleep system showed up, with insulated mattress.

The basic details

The ZenBivy Ultralight sleep system is made of the same basic parts as the Core system. There’s a quilt (down-filled), a sheet that the quilt fits to, and a mattress that the sheet fits to. They also threw in one of their updated pillows, larger and more comfortable for 2024.

The system’s basic setup is the same as well. You blow up the mattress, fit the sheet to the mattress; two straps keep it in place, and the top contours around the tapered mattress, but because this is an ultralight design, the sheet only covers about half the mattress.

These two parts are the most important. They aren’t cheap, but they’ve been carefully designed for ultra comfort. Photo: ZenBivy

Once the sheet is on the mattress, you clip the quilt to it. Inflate the pillow, slip it into the top of the sheet, hop into bed, you’re good to go!

I’m not going to geek out over all the specs, but if you care about how many ounces it weighs and what materials it uses, see that info here. It’s super-light and super-compact, and I’m not an AT through-hiker, so it’s more than good enough for me.

See the system kinda-sorta shown off in their video below, for an idea of how it all fits together:

What’s new?

There are several improvements to this system, starting with the sheet itself (available in insulated and uninsulated versions). While it looks simple, the design is updated to be more draft-free, and a couple of tabs in the top give you a place to attach your pillow, so it doesn’t slide out of place when you’re asleep. This makes the system a lot more comfortable, at least to me.

The pillow itself comes with a new soft-top system that makes it feel a lot more like your trusty pillow from home—again, more comfort.

Like the Core system, the Ultralight sleep system uses little color-coded tabs to attach the quilt to the sheet, not zippers. These are easily repaired, if something comes apart. It’s a bit more fidgety to put the system together in the dark, but I think that’s a minor complaint. Photo: Zac Kurylyk

The new ultralight mattress has R4.8 insulation, and comes with diagonal honeycomb design that’s supposed to, you guessed it, make it more comfortable.

And the most expensive piece of the system, the quilt (available in 25F and 10F ratings). It’s designed very similar to previous ZenBivy gear, but with improved anti-draft design at the top, that doesn’t add constriction to the sleeper. This keeps it warmer, but you can still kick the sleep system apart at the bottom to cool off, just like previous ZenBivy designs.

How did it work?

None of these changes sound like much, but add up all these incremental changes, and you’ve got a bed that’s easily the most comfortable and versatile sleep system I’ve ever used.

The ZenBivy Ultralight bed system (mattress, sheet, pillow, quilt) easily fit into a 10-liter bag, with room left over. I used this sleep system on camping trips in weather from near-freezing early spring to muggy mid-summer to near-freezing early fall, and the only time I was uncomfortable while sleeping was when I put the bed together incorrectly on the first trip—I ended up a bit cold, because I’d put it together wrong.

Aside from that, whether I was tent camping, hammock camping or in a cold cabin on a fishing trip, it was a fantastic piece of kit. I’ve never had a sleep system that offered such versatility from such a compact package.

I think the standout was the night I took it hammock-camping in late July. Swaying in my Hennessy Explorer beside a remote lake, I had the most comfortable sleep I can remember in a hammock, in more than a decade. The ZenBivy’s ability to fit to your body and keep you warm with the mattress under you, even when you’re folded into a hammock, makes it work better than even the underquilt I used previously.

That diagonal honeycomb design on the ultralight mattress means it doesn’t “lift” at the edges when you put weight in the middle. This mattress gave me a great sleep even on rocky ground. Photo: Zac Kurylyk

I only had one issue: When at a remote fishing camp in the spring, and at Traction eRag’s cabins in the fall, I used the ZenBivy sleep system on top of a standard bed. For whatever reason, this left me with weird pains in my neck. But when I used the ZenBivy sleep system on my Helinox cot, I had no such issues.

The bottom line is this: ZenBivy’s marketing videos are filled with talk about how they tweaked this and that to make the system more comfortable and keep out the drafts. Usually, I’d cynically dismiss this talk, but I am convinced in this case. I expect I’ll be testing other sleep systems in the years to come, but it’ll be very hard to overcome this combo.

But, one final disclaimer: This is a very expensive system. Pricing starts at $409 for the 25-degree quilt and $89 for the ultralight sheet. Add another $199 for the ultralight mattress and $75 for the large soft-topped pillow. That’s a huge chunk of the travel budget for most of us, especially in these days of tight budgets. I will always tell you to prioritize your road expenses before you go for premium gear.

But if you can afford the best, and you want it? Then you should consider this system next time you’re looking for camping comfort.

See ZenBivy’s Ultralight bed here.