I'm a big western mountaineering fan, but the flylite is like a warm "sleeping sock", i returned it! - Western Mountaineering Flylite 34 Sleeping Bag

For reference, I'm 6'-1" with an athletic build, 210 lbs, 46in chest, 36" waist, and I normally wear a LG or XL depending on the manufacturer. I am a side sleeper, and toss around as I've gotten older. I prefer sleeping bags over quilts, but I own and use quilts from time to time. My first sleeping bag was a gift for my 13th birthday, and since then I have added 6 more WM bags to my gear closet (VersaLite, Antelope GWS, MegaLite, EverLite, Sequoia, and AstraLite quilt). In the last 30 years, have backpacked thousands of miles all over the world and spend an average of 40 nights a year in a WM sleeping bag. Needless to say, I'm very familiar with WM and their best-in-class products, exceptional design, high quality material selections and craftsmanship.

On to the FlyLite. First, the expected, normal, and usual PROs for everything Western Mountaineering (sounds boring, right?) are all present in this sleeping bag, and I can say that without spending 1 night in it. I was excited for the 36F deg rating at the ultralight weight of 14.75oz at a 6'-6" length, and since my experience proves the rumor that WM rates their bags conservatively, I had no doubt I would be comfortable down to 30F.

One of the typical cons (according to some), is the hefty price tag attached to each WM product. Since I'm from the school of "buy once, cry once", I don't mind spending more for best-in-class products. I gave the FlyLite 3-Stars, so why doesn't it work for me? The SHORT zipper length limits versatility, because you can't ventilate and moderate temperature.

I didn't measure the length before I returned it, but I doubt the zipper extends more than 24" down from the collar. Why is that a problem for me? It makes getting into and out of the bag very awkward while sitting in an ultralight backpacking tent, and if you are a warm sleeper or aim to extend the bag's use, you have no way to ventilate and moderate temperature unless you squirm out of the bag. If you're using this bag in temps closer to its comfort rating or are generally a cold sleeper, then maybe ventilation isn't a big deal for you.

I get it, WM shaved weight in this design, which is exactly why I bought it. My intent with this bag was to end my summer trip dilemma between taking either the EverLite or MegaLite. The remedy? An 18" long sewn footbox and zipper for the rest of the length up to the collar. Yes, it will add less than .75oz for another 24" of zipper, but the added versatility is important to me. To some, this would be a very expensive purchase, and that versatility in 1 sleeping bag could save them money. I would expect to have the same comment about the new MonoLite, which is the same bag as the FlyLite, just without the hood.

I hope that helps! Western Mountaineering products remain the best out there! If I can convince WM to customize the FlyLite zipper length for me, I'd buy it again in a heartbeat, and one for my wife too!