platinum beacause ur pokemon dnt hav to be at a certain lvl so the computer doesnt always have a massive lvl 70 while im 58...(sad face)
Both are horrible. Battle Frontier has no real point and getting the stupid BP takes much more time than it is worth. By the time you get the 16BP for a Power item to EV train that lovable Gengar of yours, you could have had him up 5 levels already.