i dont think iv,ev training is necesary yet, but i hope the game will get harder so that it will be in the end,
as for places: i really dont understand why people bother with these diffrent spots where there are all sorts of diffrent ev pokemon
ill always just run between two stones in the left part of the railnet and battle the lvl 5ish noibats while im watching youtube or sth
just because i dont have to focus at all just presssing the same buttons and the ev come from the diffrent bracers
if the mon doesnt get any speed ev i just train as much as i can in the railnet and then reset the ev