I've tried the cheap single-strand saws - the typically broke once they got warm - about 30 seconds into a cut.

I've got a couple of the braided wire saws - they have held up much better in routine cutting tasks (trimming the errant tree limb, etc...) I would toss one of these in the kit (it also has swivels, which helped prevent kinking).

I have the "Pocket Chainsaw" - the one that comes in a little metal can. I've played around w/ it while camping & it zipped through a 4" diameter log in about 20-30 seconds. It seems fairly robust (it is also relatively heavy).

Sam