Split Second on consoles is great, but on iphone...
Here's why it sucks on iphone. The AI only trigger powerplays on you, but not other ai. The collision is way way off. You get crash even though you are far away from the area of explosion. Even when you go really really slow and touch an already triggered object, your car crash and spin like crazy. There are absolutely no physic involved in this iphone version!
After you get used to this, the game should be fun, but not quite challenging. Getting first place in all races is not as hard as on console version. It's pretty descent game compared to other iphone games, but once you finished it, you wouldn't want to play it again. And for the current price you have to pay, this is not worth it. I would say buy it on sale.