as long as it fits on a rail.. it can go between both..
IMO a tape switch is just another thing to break, i had one for awhile and it was nice but meh, not that great, having that dumb cord hanging off your gun (i had the shortest one) just to get tangled in your gear/woods/ect, this is my current setup with theI would suggest that you use a tape switch for the AR though.
I've been shopping as well - think I'll probably end up with the TLR-1. It's Streamlight's updated version of the M3, is a little brighter (on paper at least) and is an LED which is reportedly a bit more durable and longer-lasting. A coworker has one on her Glock 19 and she likes it.
and a bunch of little yellow laser stickersmmmmmmmmmmmmmmmmmmmmm SureFire and some streamlight toppings
remember don't point gun in the eye.. uh i mean laser.and a bunch of little yellow laser stickers