DP are slow. Platinum's speed was increased considerably. This is why I no longer touch my fake Pearl, which I dug up a few days ago, with its save and a ton of Pokemon on it : a) incredible slowness ; b) it's a pirate ; it won't play on a DSi ; c) ??? ; d) I'm afraid it will break and I'll lose all the stuff I trained from April until July 2009 (a small time window, but I basically ignored school and played Pokemon).
Mmyeah... I love Sinnoh as a region, but the games... just wait until Gen VI, when they'll remake Sinnoh... :D
And I play Ranger because I love the region design. And also for the Heatran. I won't bother beating Platinum and trading one over. It took me one week to beat Ranger. It will take me another year to finish my Favorite on Platinum. I seriously need to grind, since I'm in Veilstone and my Pokemon are like... Lv. 27 ? ._.'