Rode in this car last night. He had it dyno tuned to 706RWHP on E85. The sensation of acceleration is totally different than the T67 turbo setup he was using before. Power hits early and hard, revs a little further then takes another big step in power somewhere along the way. However, it doesn't hit as explosively as the T67 and other large turbos most Supra guys seem to run - it just builds very quickly and relatively linearly. Not having one big spike in power like the big singles produce, you have time to adjust to the fairly linear power increase and the broad powerband so, in some ways, it doesn't feel as fast... which is about what I expected.
It is also much quieter now than when the big single was on there.
As the Woz says: "it is AWESOME."
It's fine.