I like what this guy says: http://www.bikeforums.net/winter-cyc...l#post17251527

You'll also see a post from me in that thread about thermosoles.

I would be be willing to try the socks with the replaceable battery pack. My sense is that my cycling socks last longer than my "walking around" socks but I agree with your concern regarding length of service of these types of devices. Let's say they break after one season - is $100 a year worth it? For toasty warm feet I might pay that!