Firstly I'll start by stating that I prefer synthetic bags over down when camping in temperate conditions as experience has taught me that no matter how many precautions one takes, there's always a risk of getting your sleeping bag damp or even wet & feather is useless when damp, also synthetic bags dry quicker & are easier to wash. I use a Snugpak sleeper xtreme........warm enough in anything but extreme cold, though with a liner could probably cope with any UK weather. I'm of average build & there's room enough for at least half of me again, (I like roomy bags as when turning around the bag doesn't come with you).......heavy though (just over 2 kilos) & bulky( around 30 litres in it's stuff sack ) but with a price tag around £40 & given it's build quality,comfort & efficiency it would be hard to find a better bag.