They tested the bag according to EN13537 (which is an industry standard means of testing how warm sleeping bags are), and having used the bag for over three years, we definitely have some thoughts on these numbers (which we cover below). Im currently in the market for a new sleeping bag as my current one (Ray Mears Woodlore 4 season) is too heavy and bulky for anything more than a 2 day hike and camp. Really good quality materials used very soft and comfortable and i really like the design of the bag and the colour of black and lime.

When I got in the bag for the first time, it did indeed feel soft, it had good loft, and it was nice and warm etc. In our experience, we’ve comfortably slept in this thing in nothing but baselayers down to -5 or -6 degrees Celsius, though we wouldn’t push it further than that without a liner or without wearing a warm jacket inside. By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. Luckily, you only sleep in this thing, meaning your primary interactions with it will be in the dark.The 900gsm / 600 Fill Power duck down in the Leviathan has a fluorocarbon-free hydrophobic coating, which helps it to retain loft when it gets damp, performing better than untreated down. Packs small so fits into 85ltr rucksack bottom sleeping bag compartment, large extra storage bag is good. Condensation in my tent was quite heavy on the first night followed by a failed tape on the tent which results in the bag becoming damp on the outer shell. I then spent half the night trying to fix the zip but to no avail so I wouldn't freeze to death in the sub 4 degrees Celsius weather. I’ve had the OEX Leviathan EV 900 for a few years now, and I’ve slept in it at varying temperatures in different climates.

Ideal for temperatures around -9°C but suitable for down to -16C, this fantastic value sleeping bag is perfect for wild camping, festivals and family camping trips. It’s easy to throw this thing into the bottom of any backpack, and you can vacuum seal it in a dry bag to mould it into an optimal shape.FP ranges from 500-1000 and is a measure of the fineness of the down which as the number increases provides more loft and insulation using less down. And a "summer" rating (we had 5 deg overnight in Devon, camping in early September) is nonsense when compared to the "winter" 13 deg it will be tonight in mid November.

Initially, we were quite worried about this, wondering how long it would take until the bag was void of insulation altogether.The zip is also lined with a thick strip of protective material, which minimises snags and ensures you don’t accidentally tear the soft inner while zipping the bag up.

It lofts well (lay it out, give it a shake and give it time to expand) and it will keep you comfortably warm in minus temperatures. Ive used it this November in Scotland where temperatures just dipped below freezing and it was fine, just about. The material may be the difference - Rab is Pertex and I don't know about the quality of the down in the OEX.Presumably, this is down to the soft and thin inner that — despite being a joy to sleep in (and helps keep the weight of the sleeping bag down) — the duck feathers can easily penetrate when you roll around overnight. Growing up just south of the glorious Brecon Beacons National Park, Craig spent his childhood walking uphill. We’ve slept in it in all weather on Dartmoor National Park (including a super chilly deep winter camp where the mercury without wind chill hit -13 degrees Celsius), and we even used it at the height of the summer on a large meet up when all other bags were taken. I’d only be confident stretching this bag down to -9°C (15°F) if I had some extra thick base layers and a warm fleece to wear inside it. Looks a not unreasonable spec for the money - 600 fill power, but 900gms, whereas a Rab Ascent 700 has a higher fill power (650) but has 700gms.