The only problem I have with Platinum is that there are too many really good Pokemon available to you that I can't decide on a team, and then it's so easy to steam-roll through the game, even more so than past games. All the starters are useful, Staraptor practically breaks the game, then for teammates, you have Scyther, Houndoom, Alakazam, Gengar, Garchomp, Heracross, Floatzel, Luxray, Gyarados, Machamp, the Eeveelutions, Lucario, Rotom, Magnezone, and more to choose from.
Seems like a silly reason not to like a gen, but hey. At least they make up for it by giving you the hardest Champion ever. Diantha could learn a lot of Cynthia.