First this is a high compression engine.. 12.5:1 with direct injection.. although you can get by with 87 octane fuel, the engine really likes more octane. I run 91 octane with no ethanol since the engine seems to respond to it better...
The throttle "flare" you noticed has to do with the fact this is a drive by wire car. It does take some "adaptation" if all you've ever driven were regular cable driven thottles.
Also if it hasn't been applied, have the TSB that was mentioned earlier in this thread applied to your car, it changes the throttle maps in the computer and improves performance significantly.. not perfect like a cable driven system but much better.