Here is another more compact version, but without the easy on/off feature:
http://www.youtube.com/watch?v=O-A9kUarZMo&feature=related
On the version you linked to the studs are pretty ingenious, but they look like targets to be bent or broken if you're in the rocks alot. Maybe stumps too. But with one on each side of the truck it seems that it would work better than the one sided version I linked to.
I have heard of wheel winches. The concept seems sound. As the fellow infers in your link, it is going to be slow... But when you're alone just getting out is the goal and a shovel and jack can be damned slow, even a couple of days of repeated effort if you're really stuck.
It's funny but when I was younger and didn't have the $'s for a winch (or for lockers) I got stuck often, ussually in mud. I became very good with a shovel and a jack. Now that I am older (perhaps wiser and less inclined to do go mudding or where I'm likely to get stuck) and have had a winch (and lockers) on the last couple of Jeeps I haven't had to use the winches for self recovery. Close a couple of times though, and for recovering others, but not for recovering my Jeeps.
The wheel winch seems like a reasonable alternative. One plus over a permanently mounted winch is that you could use the wheel winch to pull yourself out backwards as well as forwards. Turning a stuck truck with a winch 180* to head back the way you came can be a nightmare with lots of potential for damage.
Do you have a source in the US? I would consider one for my Suburban, which doesn't have a winch and which was a ***** to dig and pull out the one time I've gotten stuck in it.
JPK