Got the Bubs mounted today, and also did the AIS plug.
Runs good, no discernable lean spots in the fuel delivery. I have made no jetting or air intake changes at all. Mounting was fairly easy, and they sound pretty good. I had made some mods to the stock pipes, so there is not a huge difference in noise around town, at moderate speeds, but the Bubs do 'bark' a bit more on advancing throttle. They seem to radiate more sound to the sides, and have a slightly deeper 'runmbly' tone when idling. All in all, not too loud, just about right.
Worth the bucks. I guess in a year, I'll give a report on those endcaps.