Offering unrivalled comfort in its weight class, the Cloud 800 20° sleeping bag from Sierra Designs gives you a standout sleep system for 3-season, cold-weather camping and trekking. I was really skeptical with the zipper-less design of the bag but it proved to be a non-issue. It's quite a warm bag but I'm generally a warm sleeper so I may not the be the best gauge for that, but it seems to do the job well in that regard.

I must first admit that the sleeping bag is too wide for me leaving empty space in it, and I probably should have bought the women's version. I guess that part of how it was designed, was to give you extra room for comfort. Plus, I’m relatively a cold sleeper. Temperature Mapping System – This sleeping bag features a sleeping pad sleeve that keeps pad under you, for comfort and warmth and replaces unnecessary bottom insulationOne thing we may have to note is the sewn-through design of the Cloud 800. Most bags and quilts we've tested use some sort of continuous baffle design. Continuous baffles theoretically keep more of the down fill between you and the outside, while a sewn-through design adds more opportunities for your body to be pressed next to the thin shell fabric at the sewn seams. The shell material doesn't add much insulation from nighttime temperatures. Most bags and quilts we've tested opt for the continuous baffle design as a way to tweak the warmth of the bag, as the continuous baffles allow you to shake the down through different parts of the bag.

This womens version has 419g of 800 Fill Power DriDown that has a -3°C Comfort Limit so its good for two to three season use, particularly if you're a warm sleeper. The fabrics used are 15D so they are lightweight but also more than many of the lightest bags out there. The dimensions of the bag are generous so it would suit someone after a larger bag, someone who moves around a lot at night and warm sleepers. The overall weight is really impressive given all the features too. I have only used this bag for three nights so far. The conditions were fair (no rain). This is my second Sierra Designs sleeping bag and I am a dedicated customer!

Conclusion

This version has 419g of 800 Fill Power DriDown that has a -3°C Comfort Limit so its good for two to three season use, particularly if you're a warm sleeper. The fabrics used are 15D so they are lightweight but also more than many of the lightest bags out there. The dimensions of the bag are generous so it would suit someone after a larger bag, someone who moves around a lot at night and warm sleepers. The overall weight is really impressive given all the features too. So, instead, there’s a rear sleeve to accommodate your sleeping mat. This makes it impractical to twist the bag around, so it may not suit side sleepers – though the roomy fit makes it relatively easy to move around inside the bag itself. It does, however, mean that you really need a well-insulated sleeping mat underneath you to guarantee you stay warm.

The Sierra Designs Cloud 800 35 features a zipperless footbox vent, and zipperless comforter design making it very easy to lounge around camp while wearing the bag itself as an insulation layer. I used it on several multi-day hikes at temps between 2-10 Celsius, with a Therm-A-Rest Neoair Xlite pad and inside a tent. I’ve included some pictures of this bag in its storage and stuff bags with comparison items. With a compression bag you could get it even smaller if that’s your preference.I finally got to try this bag out this past weekend on the Buffalo River Trail in Arkansas. The temperatures at night ranged from around 45-55° so I wasn't truly able to test the warmth of the bag. I found no drafts in the bag, except if you don't put your feet in the right way, they slide out of the footbox in the slot.

Durability: It’s a well-made bag, the fabric is pretty thin and feels gentle, but so far, I had zero issues with it or with the seams. The filling is leaking constantly, but mostly it's just small feathers and down fragments. However, the EN 13537 European Standard does not apply to down-filled sleeping bags with a fill weight of more than 800g; for those bags, you will have to rely on the manufacturer's experience and technical expertise, which is often more accurate!Disclosure : Trailspace received a sample of this product from the brand for field testing and review. The product was assigned by Trailspace to this volunteer Review Corps member. Synthetic fabrics used for outdoor gear are often ripstop, a textile weaving technique that provides materials with abrasion resistance. Ripstop fabrics have a visible grid-like pattern of threads that protects against snags and scratches—sort of like wired glass. While ripstop doesn't make a piece of clothing or gear invincible, it certainly helps lengthen the lifespan of a product and prevents from accidental cuts from your camping knife or a sharp tree branch. An adjustable hood can be cinched for added protection while an innovative self-sealing foot vent lets you slip your feet free from the bag for fast and easy ventilation on warmer nights.