Got the rebuilt supercharger back from pwcmuscle and reinstalled it. They included the original parts when they shipped it back as evidence that they actually changed them. Is there any reason to keep those? That whole process was quite painless. 30 mins to remove the supercharger and 20 to put it back in. Took her on a maiden voyage today and it ran well. Got to 50 mph indicated but the speedo is a bit slow vs. GPS. I didn't check at top speed but at 25 mph indicated on the speedo my iPhone showed 30 mph. So, it seems to have attained the expected top speed of 55+ mph.
I did pick up on a barely perceptible miss when cruising at WOT. It was so subtle I'm not totally convinced I wasn't imagining it. It only did it cruising at wot, not when at WOT under acceleration or when goofing around spinning and what not at WOT. The gas was from August and may not be 91+ octane. I topped it off with 13 gallons of ethanol free 93 octane. We'll see if that takes care of it.
The whole low speed handling was interesting. It was very responsive once I got my bearings with it. My old 2 stroke sea doos didn't have the pretend "neutral" or "reverse" like this boat has. It handles like a sports car though compared to my 23' MasterCraft (handles like the tug boat that it is).