Hmm, I hadn't even thought of the seasonal confusion aspect. That might be a deal breaker for me, because I usually run cold, and I don't break out sleeveless tops until it's pretty darn hot. It would have to be made of really lightweight leather.
It's interesting to know that people don't seem to have a problem with sweating on the leather. Sounds like maybe it's something worth trying when I feel like I have the funds.