Just tested it out on Jayce.
With the 15% cdr reduction cap from Ultimate Hat with a 45% cdr, Jayce can transform every 2.8 seconds. This is ridiculously broken, as any fellow Jayce mains will agree that transformation cooldowns make or break many fights. This is just enough time to use all skills on one form, transfer to the other form, get all three skills off, and transform back with one or two skills already being back up, your q's for example.
Can't wait to utilise this again in game. Hard carries are once more a very easy possibility with Jayce and other transforming champs like Nid and Elise. Karma is about to be mega broken also.