I think it really comes down to personal opinion:
Going with a 3.0 pitch allows you to use a 7-tooth extrovert-style Avid driver. But, then you are stuck with the 7-tooth driver, (the 8-tooth 3.0 pitch has less clearance) I got mountainhorse's data sheet somewhere around here.....
If you're going to do a D&R kit, you have to decide if you want even more clearance, or if your brand of kit will give you the clearance you want.
I'm betting that I'm going to get enough clearance with my D&R kit to clear the longer track paddles, so I'm sticking with the factory (2.86 pitch) drivers, for now. If the ice buildup issue becomes a problem, I'll swap to dual Whal (extrovert-style) drivers in the same pitch, and get rid of that third center driver.
That's my plan.... for now.
I have ordered the FTX D&R kit and the track already, but they are not here, but neither is my sled, so I'm stuck just cleaning the garage.
By the thread referenced by VINNEE, you can see I went through all of this already. Send me a PM if you want to chat. Ill tell you what I went through, and what I learned, and you can tell me what you know, and maybe we can each learn something.
PE