They are excellent motors, but somewhat expensive; whether its worth paying out that much money depends on how much performance you need/want, and how much money you have to spend. I would check the buggy subforum to see if anyone is already using them in their buggies (I would almost guarantee it), but I think the 1515 1y is perfect for 4s operation. The motor will also have plenty of braking force, its more a case of tuning the esc to give the desired amount- too much and you endo, not enough and you will overshoot corners. You can always disable the reverse/brakes o the MM and run mech brakes, which is nice if you come from a nitro background. Mech brakes is also easier on the esc ( the MM is a bit diddy in size ).