There is nothing wrong with the turmoil. I didn't get to see one yet but the mayhem had great quality parts especially for the price and I wouldn't expect anything less from the turmoil. You get a MUCH better engine and electronics package from the turmoil as well so you don't need to upgrade them like you would the hyper 7 RTR. With the hyper 7 you would atlease need to change the servos but I'd highly recommend replacing the radio as well. I'm pretty sure the hyper 8 RTR has the same dirt cheap electronics.

The mayhem can handle track well but it needs quite a bit of setting up and even then it wont be quite as good as the hyper 8 on track. I can't say anything about how the turmoil handles track right out of the box.