Played it at a friend's house. Personally I tried out every type of controls find, but I found the controls to be too wonky in order to do basic things. Online was alright, MUCH better than SSBB which was a plus buti don't get why I couldn't just play my friends online but had to let others play as well. I like the motorcycles but it looks awkward when I think about it as a Mario Kart game. It's a good game, but not a must buy for me.
You can turn off CPU's in the options/rules menu. I just bought the game 2 days ago and I love it, not as much as Brawl though. I do kinda dislike the team system for battle mode, but the battle courses are really good, except for cookie land, worst place ever.