The gameplay is extremely fast paced. Which is what you guys wanted, I know, but I was still caught a little off guard. At the moment I still like SR and TT better than CS; I think I'll only be playing CS when I want a really fast game to help me unwind after the day.
Also, as other people have mentioned: mobility seems like an incredibly important stat in CS. I realize that there are speed shrines, but even so, when I play a slower character I feel a lot less useful compared to when I play a character with some kind of movement boost. The primary way of winning the game is by capturing and holding towers. A fast champ can capture more towers than a slower champ, and be safer while capturing too since they can get away easier. A fast champ can also come to the defense of a node more quickly than a slow champ.
Sustainability also seems pretty strong - due to the fast paced nature of Dominion, having to keep going back to base to heal/get mana can easily put your team at a disadvantage and let the enemies capture a point or two. Again, I know there are map features meant to help out champs without sustain, but they don't feel incredibly effective.