If your car has hesitation with throttle application, your best fix well be a better air filter and/or better gas. I don't think that the TSB did anything that could cause that as it (to my knowledge) only affected how the clutches shift and the ABS for holding the car on a grade after you switch from brake to accelerator.
I know that hesitation is frustrating, a put 87 octane in a week or so ago. I felt like there was something wrong with my car. After swapping back to 93, all is good.
Don't underestimate the effect that heat has on our engines. While (imho) the engines perform really well, they seem hyper-sensitive to small environmental changes. This is obviously not a fact, just my observation in comparison to my mechanical background.
FocusFest 2013: Best of Show
Gateway FFW: Show Class Outstanding
September '13 ROTM
Hatch Nation #161