The TT is no comparison to the 370 in performance, the TTS is close. Even though it is rated for 265hp, I think it is making closer to 300HP. I think TTS is due for a minor refresh, so it might not be a bad idea to wait or lowball the dealer for one. TT just got a tweak in torque, but still ways to go in terms of performance to the Z.
With all that said, I still want one because that is a better vehicle for New England and my wife can drive the automatic.
I see new TTS in the low 40s with the TT mildly packaged for high 30s. TTS doesn't get a lot of love from non track users because the giant turbo they use create lots of lag, but it is way superior at the track.
Buy me one and I will give you my Z