I don't have them on my boat and I can't offer any input as to how well they will work on yours.
I was on a friends boat a couple weeks ago, a 23' aluminum, he fitted them about 6 months ago. They worked very well, as they claim they do, on a rough Pacific with quarter sea, I was impressed.
I would consider installing them on my boat but I don't want to drill more holes on my transom.