scott,
I’m wondering the same thing, I’ve been reading up on the RepRap forum, and it seems that with PLA having two fans (one pointed toward the upper part of the hot end, the other toward the print) would be the way to go. Otherwise you’d need to cut down on printing speed if you don’t cool the print.
You know, considering how I’ve have very few problems printing with ABS, and the problems I keep reading on the forums about PLA, I don’t see any reason to want to print with PLA. But I admit I haven’t printed anything very large yet. In any case my AO-100’s print bed is only 200x190mm.