50+ 100% IVs... WTF.
I'm 34 and I don't have a single perfect IV pokemon. Either I'm extremely unlucky, or there are tons of people out there who don't know what a perfect IV is.
Basically I try to keep at least 1 of each. Of those I only keep 1 of, I keep the highest IV, then CP. We're talking like Pidgey, Ratatta, Spinnarak, Hootoot, Furret, Paras, Mankey, Murkrow... and on and on.
I don't think I've ever transferred a dratini/larvitar or any of their evolutions. I have all of the legendaries I've caught. Though I am considering take that down to at most 6 of any given one. Axing the lower IVs.
If its one I think may be useful, if its below 80% it gets the axe, unless of course its the only one I have and I don't have one above 80% then it stays... for now.