PokeVision is useful but still flawed, it does not show you ALL the pokemon around you, only ones that other players have seen.
There is a few mobile apps being made to show you the IV's of pokemon so you don't need to make a ton of calculations your self, I will post them when they are finished.
Just hit level 25 and near 26, it takes about 20,000,000 XP total to reach max level.
Also officially caught over 1,000 Pokemon woo! Gold badge grind!
Also, all the data currently available shows that pokemon nests have a specific IV range which is not as good as catching one in the wild.