Just to give you an idea, I run a 25 Yamaha with a 4 blade powertech cupped prop. I also have a powertech 3 blade, both stainless. The pitch is different between the 2 but that's normal when going with a 3-4 blade. The 4 blade performance wise is my favorite prop. Speeds are typically in the 30 mph range but with a jack plate this prop really shines. Boat jumps on plane very quickly, in seconds actually, and allows sufficient water pressure to run in the fully jacked position. I normally run this prop while I fish shallow areas which is 99.9% of the time and it's perfect. If I'm doing long deeper water runs then I can switch to the 3 blade and get every bit of rpms and speed out of the little motor. Speeds jump 3-4 mph and once the rpms are up the boat launches like a rocket. Just not as quickly as the 4 blade. The 3 blade also needs more of the motor in the water to be efficient so shallow planing suffers a tad. Basically, if your not planning on getting an adjustable hydraulic/electric jackplate, tabs or compression plate then a cupped 4 blade may not give you the performance your looking for. It may plane a little quicker and give you a better hole shot but your top end may suffer and you may not be happy with the performance. These are just my findings and I hope they help. It took me a while to get the best pitch for either prop and if you switch sizes make sure you have a tach installed. Without a tach, your tuning blind. Hope this helps..