Most of the toys that we have that use watch batteries are bullet vibes that are intended for complimentary use to another toy (ie. the pouch of a strapon harness, the back of our Feeldoe, in a cockring, etc.). I assume the choice is for something that's not terribly large. I've never been particularly excited by them, since they usually have one speed (not always), and generally don't provide that much stimulation. Lifespan has been okay, since most use 3 or so watch batteries and don't draw that much power. Still kind of indifferent to them. I usually like something with more buzz.

mine die right away...atm i will not buy anymore that take watch batteries