I have been running a 26 Quad IV O/T on a XB03/225 PM at 4000' altitude for a little over a year. The boat had a 30 Chopper II on it when I purchased it. I can turn the Chopper to 6200 rpm/85 mph, and can turn the 26 Quad IV to 6600 rpm/85 mph. Not a big difference in hole shot between the two with a light load (just me), but the Quad IV is better with a heavier load. What I have noticed, is the Quad IV comes out of the hole okay with one or two people in the boat, starts bogging down with three, and really struggles with four people in the boat.
The only thing I am not completely satisfied with on the Quad IV is the hole shot. It will rev to 4000 right off, climb to 5000 just before breaking over, and then seems to let go with rpm's shooting to 6300 as it breaks over, dropping back down once it hooks up. It feels like it's loosing bite when it shouldn't, and I think this is what is affecting hole shot with a load. The Choppers I have run rev to 4000, climb to 5000, but don't "let go" on break over like the Quad IV does.
I have also run the following props on the same set up: 22 Chopper (small ear), 23 High 5 and 21 Trophy, all loaned from a local dealer (looking for a ski/play prop). Surprisingly, the 22 small ear chopper comes out of the hole better with 4 people in the boat than with any of the others except the High 5. The Quad IV drives and handles nicer than any of the others by far. The engine seems smoother and quieter, and the ride quality is definitely better, especially in rough water. We have tried water skiing with the Quad IV with mixed relults--worked great at low altitude, but wouldn't pull an adult on 2 skiis at 4000'. This tells me a 24 Quad IV may have been a better choice for heavy loads/skiing. I may give Hydromotive a call and see if there is any tweaking thay can do to improve my hole shot. If successful, I couldn't ask for more in a prop.