The BRZ is smaller, between a Miata and the Genesis, and comes in at 500lbs less than the Turbo, and 600lbs less than the V6. I think the Genesis would be easier to live with day-to-day, but the BRZ should be more fun to drive and handle a LOT better.
Subaru has a list of cars they expect people to cross-shop:
Honda Civic Si
Hyundai Genesis Coupe
Mazda MX-5 Miata
Mini Cooper Coupe S
Volkswagen Golf GTI
Personally, the Honda, Mini, and VW are off my list because they are FWD. The Miata is too small and only a 2-seater, with half the cargo space. And the Genesis is too big and heavy, not to mention a Hyundai (parts are a bitch to get).
Even if only the Scion FR-S came to the states, I'd want it. It hits all the right points in my opinion.