I haven't tried the British one yet, so it might be the exception, but I think I've tried everything else. I've concluded they come in two varieties- sucks, and really sucks.

The manual chainsaw is good, I've played with one. I have a folding pruning saw- blade is about 10" long, and I've taken 6" material with it. It isn't always happy with oak or some maples, but if you stick to the little stuff you're good. But what I usually have on me is the saw of a SAK or my Leatherman, and for most things I've done in terms of shelter building they are fine.