I'm glad that you got her up and running and she's running smoooooth...
To perform the idle drop, you will need a top of the line DVOM with an inductive pick-up, that reads down to 1 rpm. I use either the shops OTC, or my Fluke. It's a very tricky procedure. If your willing to take the time to do it properly, send me a PM and we'll talk over the phone. I also feel that the "color tune" is nothing but a gimmick. It may work ok for another application, such as a lawnmower or a snowmobile, but not an ST. We can tune using vacuum and rpm readings.
I still feel as if the 1 7/8 is a just a squeak rich and would be better set to 1 3/4 as I suggested. If you were to drill a 3/8" hole in each muffler baffle, you could successfully leave it at 1 7/8. The nice thing about putting in those #40's, is that you won't need to use the choke under 50 deg F. Just crank the engine over and roll the throttle a little bit and she'll fire right up. Use your throttle lock to hold 1200-1400 rpm to warm it up.
The ultimate question you have here, is how does the ST1100 stack up against Harley. No matter what, ultimately your ST will win(unless your up against a full racing S&S). Your ST will take them off the line and for top end easily. Off the line, launch hard. Preload and speed shift at 7500 rpm. Redline is 8000 rpm and the rev limiter kicks in at 8500. The ST doesn't make any usable power above 7500. For top end, snick her down into 4th and hold it there. Done... Top speed runs can only be done in 4th. 5th is too high and you'll never build enough high rpm horsepower. However, if your in a mid-range roll-on, they will pull away. The Harley has tremendous torque. Be prepared to tap her down 2 gears to keep up and stay even. Once your holding, shift at 7500 rpm. Leave it in 4th gear to finish him off. After you reach 90 mph you'll sail right by.
You can fool many a sport bike too. Remember that the ST pulls like a tractor. You'll have the advantage for roll-on's. You'll out-pull a sport bike, but after they catch up, it's all over...