I just recently restarted my platinum version. I really missed going through the storyline, and I wantef to use new pokemon. I am currently using a grass monotype team. I really just get bored battling the battle fronteir all the time.
Well, I admit I'm guilty of compulsively restarting the games when I want to do something even a little differently. I like beginning a new adventure, but at the same time, if I allow myself to get far enough into the games, I become so attached to the Pokemon I have and how powerful they've become that I don't want to restart.
I still remember my old Flygon, Tetsuhiko, from my Emerald Version who I digitally slaughtered when I erased the game...and still haven't even began a new journey. D;
I restart my games if at least one of the following holds true:
a) My save file gets deleted.
--> In that case, I would have no other choice but to restart my game, wouldn't I? (Man, I hate pirated copies of games...)
b) If I'm not too attached with my game.
--> I tend to get too attached to my Pokemon games. I just couldn't let all of that hard work go to waste, could I?
... Although, HG/SS could be another story... I'll probably not get too attached to those games...