I don't know, a stage 2 STi is no slouch...once Cobb releases an AP for it, the '15 STi might just be the "both" you're looking for.
I know that, coming from my stage 3 '12 WRX, I was expecting my new STi to feel slow (since it is rated at about 100 less crank hp than my modded WRX was). Honestly, this car is more fun to drive in every way. I don't feel myself lacking for straight line acceleration. I can throw it in the corners at speeds that would have sent my WRX skidding into a ditch, and the STi just yawns and asks, "Is that all you've got?" It goes where you point it, and it goes there pretty quickly, with grip and a solid planted feel. The interior is still not Lexus, but I don't want or need that. The seats are nice, the steering wheel is awesome, the wheels are great, the exhaust sounds mean without droning or being obnoxious, and I've got enough little amenities to make me happy with my purchase. I've never been so happy with a car, or enjoyed a car so much in stock form, ever.
Having said that, I'm almost giddy thinking about what stage 2 would feel like, or even stage 1. Sure, still not the fastest straight line car ever, but for the money and versatility it can't be bested by any car currently in production.
All in all, I have to agree with Subaru saying this is the best STi ever built.