The sound bug is still not resolved (pro-tip, read the Unity docs..), and the optimization is horrible. If only considering this "game" on its technical merits, I'd expect better quality from an indie team of 3 kids, not a company bankrolled by Google. Seemingly every update makes this app worse.
That's the tech. The so-called "game design" is tragic.
The "Nearby" or "Sightings" mechanic exists solely to frustrate players. The spawning is a joke: how many goddamn Rattata's does one person need? Now, that might not be so bad, *if* it was possible to trade with other players. A "multiplayer" game with absolutely zero direct interaction?
Niantic, login to the GDC vault or read a bunch of articles on Gamasutra and learn how you make games. Your current efforts are pathetic.