Greg makes a lot of good points.

Only thing I'd add. The IT7 drivers I know (good friends and good racers all) generally say the following about moving to a "traditional" IT class:

1. They already have the car and the cage, and spares, and they want to stay in the 1st Gen chassis.

2. They don't want to go to B because of cage issues, and wheel issues (they mostly run on 13X7s right now).

3. They don't want to run ITS in 2nd Gen cars because those cars are viewed as more finicky, and more importantly, they lose there spec tire (Toyos) that last (for many of them) a season or sometimes more.

Just throwing that into the mix for thoughts.