I dont' know about the Mugen handling better simply because give the Turmoil to any pro driver and they'll be able to put it in the winners circle. Any car can win on any day, it's who's behind the wheel that matters.
Durability is the difference between the 2 buggies.
You can't go wrong with the standard mbx5 and at half the price of everything else, it's an even better deal.