Well, I was a bit bummed out about no Gym Leader Castle...didn't miss TR that much, though. Cipher was pretty damn fierce, I must say. They were just plain stupid in XD, but in Colosseum they had a motive, making them my favorite bad guys right behind TR.
Eh, I don't have one...kinda want one, kinda don't. Blehh.
The only glitch/cheat I've done in GSC was in my current Silver where I got all the starters. ^_^