I have 3 pairs. My new red Sidis with Speedplays for road riding that I wear most of the time, my old light blue Sidis, which I kept, in case my red ones get wet, and my Sidis that are mountain bike shoes, with spd cleats. I wear those when I ride my Jamis hybrid, my mountain bike (hasn't happened yet this year), or go to spin (which won't happen this year, since i bagged my gym membership).
I have 3 pairs of booties, one for my mtb shoes and the others for my road shoes. I got one pair of Gore booties last winter and they fit very awkwardly. I can't explain it, but it's like they don't go over my shoe correctly and I can barely get the velcro snapped to the other side. They are the right size, so not sure what's wrong.
I do resort to the chemical warmers, especially when I commuted and it was 45 or below in the AM. I know it's wasteful, but I have a huge box which I purchased for x country skiing, so they will last me awhile.