Highest logged speed on mine, 39.6 mph. WOT with 2-4 aboard and full gas, smooth water/little wind - about 36.
This at sea level on the E. FL intracoastal. Dealer said to expect mid-30s, so he was spot on. I admit I showed a skeptical look when he said that.
Once the engine warranty expires I plan to do at least the ribbon delete. A couple more mph would be welcome. My previous boat, an '04 Sea-Doo Sportster 4-TEC once did 51 mph GPS on a smooth lake. Other than the "aw it's slower!" at first, I really don't miss the difference.
Sure, it'd be nice if it was faster - but where I boat 90+% of the time, the speed limit is max 25-30 mph. It cruises nicely at 5900-6300 rpm depending on load/wind. I also appreciate the (newer) hull design and spaciousness. Last - gas: on several long days, at most I've used about a half of the 40 gal tank. Any faster options - twins, supercharged... all use more gas and/or premium.