Nice post, thanks for sharing, I've been considering a wire saw to include in my smaller kits, but I've usually heard such negative things about them in the past that I've not followed through. Add to that my own experiences with the wire saws they used to include in the cheap, rambo knockoff hollow handle knives years ago (so cheap that when they got just a little hot they would break in half). Plus, the only one I was considering was the BCB and those are hard to come by in the US, but the pro force is much more accessible.
There are some improvements on the wire saw to consider besides bending it into a bow: a couple years back someone made a compact saw using sturdy chain saw chain and well constructed loop handles on either end ...
I don't remember where I got the chain saw chain model but I think it was local to WA somewhere, interested folks could look for earlier posts on this forum as I'm pretty sure we discussed it.
This might help. There are two main makers of the chain saw type collapsible saws you mentioned. One is the saber cut by Ultimate Survival Technologies:
http://www.amazon.com/Ultimate-Survival-Technologies-SaberCut-Black/dp/B001H9N8C0The other is the original (I think) pocket chain saw:
http://www.pocketchainsaw.com/There may be others out there, but I am pretty sure these are the two that Doug Ritter discusses here:
http://www.equipped.org/saws.htmUsual disclaimers apply.