Personally if I weren't planning on tracking I think a2a is fine depending on I guess where you live and if you plan on driving in 100 degree weather. I've hit air intake temps of 145's or so on the highway while doing pulls and the highest I've seen has been in stand still traffic, but that's not really a concern since I'm aware of it and I'm not on the boost then or running the car hard when I know the temps are a little higher.
I guess it's more for a peace of mind sometimes, my a2a has been fine but since I'm planning on hitting the track and want more power down the line a2w is really the way to go in my opinion.