I find it pretty fun, but it's clearly still a work-in-progress and not something for me to sink a ton of time and effort into yet. Got to level 10 yesterday, have been refusing to join a team because I saw gym battles from both the internet and my little brother's side (He also joined Instinct), and they're kind of unfortunately designed such that there's a clear "meta" of which pokemon to take and use. I'd rather wait until they make the teams more than just "You can do battles" before I actually pick one. Or if they make Team Rocket an option down the line you better believe I'm joining them :V
I've also gotten over the 300CP mark with two pokes, one of which is a Kadabra I've nicknamed to be the same as my Pokemon Red main, so that's nice. The leaders are silly and Tumblr characterizations of them have made them even sillier, and I love it.