@windy, Sativa is the friendlier of the two imho. I have done both. Indica takes a little getting used to. It's really stoney. I don't mind it (should say didn't, as I'm sober), but it used to make me feel uncomfortable like I was too stoned. that's my two cents!
There can be a distinctive difference but often there isn't. A lot of modern strains contain elements of both.