No, they're still steel rims. Just better ones than what was on there (no pitting). I looked into the Sun CR-18 rims, which come in 32 and 40 spoke, and it will cost about $70 just for the rims, extra if I change spokes and nipples, and still more if I pay the shop to do it. Maybe someday; need to get the saddle figured out first. Is the B66S just shorter than the B66?
Any other difference?

My wife's not that tough; I had replaced the stock 18T cog with a 22T--the 22T was too easy. I split the difference and put a 20T on for her.