The problem when this app on release date is the developer, Niantic didn't know how much people will play this app. Niantic should already know how much people played Pokemon like millions of people or so. That resulted with random server downtimes.
I played Pokemon Go couple of times. I was hoping this app have something that I could play everyday in my phone, but for now I don't think this game is worth it for me. I know the purpose of this app is to go outside, catch Pokemon, raise it, take on gyms, battle people, etc. I absolutely love Pokemon, but I just don't go outside that often.
There were some notable issues that I fear before this game released as like people using in app in the car and doesn't pay attention on the road or any tragic problems irl.
Should I recommend this game? If you truly LOVE Pokemon and you usually go to work (or school), or often go outside then this game is for you. For me, no.