The carbed version is appealing due to relative simplicity and lower cost. But, having recently kicked the carb habit at chez Earp I'm really enjoying EFI and would choose the EFI IT7R option.

However, I suspect the EFI IT7R option will take more money and loads more development time. And of course the performance of that package is going to necessitate further changes to other subsystems of the car.

In the end, neither are IT7 in the current form.

It appears that people are finding ways to continue racing the 13B in ITS. Was the 13B considered for "IT7R"? Although it'll face the same problems as the 12A at some point. And, the Renesis might also experience difficulties with cores at some point far down the road now that Mazda as pulled the plug on the Dorito motor.