I have a 25 motion with 300 pro max motors and first had 5.5 inch cmc jack plates. In smooth water the boat would start to hop around 45 mph and wouldn't settle down until almost 90. I did some measuring and had some other things to do over last winter so I got rid of the jack plates. I really like what it did as now I can cruise at 60 before it starts to porpoise and then by 80 it is settled down.

I think top end might be down 1 or 2 mph but to me that is well worth it. I have noticed the slim line and I say go for it. They were just a little more than I wanted to spend.

Call STR before buying as you may have to drill new holes in your transom and I think STR work with you to try to ultize the 4 existing holes.