I had them on my old inflatable. They worked very well for what I wanted them for, and and that was to be able to plane with a heavier load and only a 3.5hp outboard.
Don't expect any increase in top end speed, but the boat will ride better and you'll be able to cruise at lower rpm.
I bought them a couple of years ago when the pound was stonger, eventually sold them on ebay without making a loss.
Yankee 154
