Gary said:
good bags - get new if you can and get long lengths. Oh and use with a bivi bag to protect from damp.
Quoted for truth.
Living in what is traditionally an army town, these things are all over the place. The local surplus shop sells them new for forty sobs, which is certainly not to be sneezed at.
I have one of these myself and it is certainly a great bag for the money (the built-in groundsheet is a stroke of genius), but I might invest in one that rolls up to a smaller size if I really feel the need. Also, after a thorough soaking I recently recieved in it, I found out that the down filled bag doesn't dry out nearly as slowly as I was led to believe it would.
I'd say go for it, myself; they're very warm and definitely hard-wearing. For the money I'd say there's no better.