Whenever ya go to a 4 blade, you drop down 1" in pitch. For example if you are turning a 23" 3 blade you'd go to a 22" 4 blade. You would gain- a better hole shot, better acceleration, much better steering (with conventional cables set-up), and will drop about 1 mph at full speed. So, if you are turning a 23, going up to a 25 4 blade would be like a 26" 3 blade. Way too much prop IMO.