Unless you increase the air flow through the intake and exhaust, the large bore throttle body probably won't be too beneficial. This would include larger volume air intake, and better flowing exhaust (i.e. Borla/Banks header, hi-flow cat/muffler, larger exhaust pipe). This is a lot money per pony (hp) gained. You may feel a little better throttle response? Also, not too sure how a mopar OBDII puter handles such changes. Perhaps someone on here has experience with it. The large bore TB with a cold air intake does sound a bit cooler when you go WOT. That is if it doesn't whistle on you.
The only benefit of the throttle body spacer, for me anyway, was better clearance/access to TB sensors and better alignment with the throttle and tranny "kick down" cables. But my set up is pretty far away from stock. Otherwise, as per above, a waste of money.
Not trying to be a Debbie Downer. It may help in the higher rpm ranges.