[cstreit]

I used a throat mic. on mine because the regular mouth microphone picked up to much ambient noise from the racecar. Worked well and I didn't have to worrky about it staying on inside my helmet.

Programmability of channels is nice, at least have a selection of 6-10 because others could be on your frequency at any given track. Output power varies but I'd invest in the max transmission permissable if you're road-racing to ensure you're not out of range.

A remote antennae also helps extend range...