Have to agree with Fetzo, the GT is pretty useless. Basically it's the GP with tighter T1 and a chicane after that.
But the North is going to be a great addition! It uses the part of the track I've always enjoyed, but are only used in 2 configs (which are pretty much the same).
Alltho the pits are going to be too small, just try to get your FXR out of the pits in AS Cadet, it's kinda narrow.