I tried it during beta, and it wasn't bad. Very much like Ingress as it's using the same landmarks. The full release seems a little more polished, but there's not much to the game, personally other than just waiting for a pokemon to show up while you're walking around. Then you get to look like the weirdo who's playing on their phone in a random area while you throw pokeballs at a rattata.
Haha, but definitely give it a try. I was super into it for a few days but the novelty wore off pretty quickly.