OEX - Leviathan EV 900

I currently use the oex leviathan 900 as my 4 season bag. It's substantially more expensive than the berghaus transition, but in the world of down sleeping bags it's pretty cheap. Packs down super small and it very warm

The oex leviathan, leaks allot of feathers but not the actual down, this doesn’t change the comfort temp

I've done several distinctly sub-zero camps in mine- under a tarp and in a hammock, and always paired with a R3.8 mat. Primaloft jacket, trousers & booties too. Cosy every time. The baffles and cinch cords make a massive difference to heat retention. Lofts quickly and fully even after several hours of compression. Always stored uncompressed though. Does lose feathers here and there as pointed out by others. Picked it up in a GoOutdoors sale for somewhere around £120-140 I think, and at that price it's a bargain.

I'm very fond of my oex leviathan 900, it has gone up a bit in price in recent years but I snagged mine for £90 from go outdoors a few years a go. I do a lot of winter camping at elevation with snow and never once felt cold in it though I am a warm sleeper, often have to just sleep in my boxers. The main downside to that bag is that it's down so it must be kept in a good dry sack. And between trips don't store it uncompressed to keep it's loft. On the flip side my mate that I usually camp with uses a bag comparable to MW1400 and never complains about being cold even in the snow. I personally prefer to spend a little extra on my gear especially my sleep system so I have confidence that I'm going to be warm and comfy

The Leviathan is a good bag but it can seem like you’re waking up with feathers everywhere sometimes.

Sleeping pad with R2 isn’t good enough for uk winters stacked or not you will be cold. Aim for at least R4 Big Agnes Rapide SL is a fantastic option and comfortable all year round i pair mine with a EE 0 degree quilt and im toasty down to -5 . Rab bags are excellent highly recommend them definitely stay away from Leviathan they’re not capable of handling 5o .

Ive been used the leviathan a couple of times now and havent had any major issues. It does shed feathers from new, and the zip gets stuck very often. Maybe I havent owned it long enough for it to develop the cold spots but its not something ive experienced. Overall at its price im reasonably happy with it, but wouldn't expect it to last multiple years and have the same performance.

I've slept in mine down to about 0 degrees and I think it could go colder if you're careful to do up all the baffles and flaps to properly trap the warm air. -6 is probably as low as I would want to go with it, and I'm a fairly warm sleeper.

Oex leviathan 900 is a decent cheap bag, i used mine for a while it is a decent bag especially for the price, go outdoors sells em for £120 at the moment , then i got a rab mythic 600 for £350 barley used on eBay, apart from weight and pack size it’s just as functional does the same job of keeping me warm as the more expensive bag. Don’t be afraid of buying used stuff on eBay is my advice or if you wanna buy new the oex leviathan ev 900 are great budget sleeping bags just check all the baffles are filled with down, first one got i had to exchange cause it was missing down in the foot box.

I had the mountain warehouse bag you are talking about and for the money it is brilliant. I have used it to just below freezing and was fine. I changed it because of the weight and even more so the bulk but for the money to get you going I’ve never found better. My wife bought an OEX synthetic bag claiming almost identical comfort rating but nearly half the weight and pack size. I was skeptical but overruled. At about 5 degrees she was really cold so I bought her an OEX leviathan down bag. It is about 4 times the price of her synthetic but she was warm at -4. Hope this is of some help. Please ask if there is anything else I can tell you.