Yes I had some small ones on a 25hp fourstroke, 12.5ft SIB once. They worked ok. Getting them adjusted so they rise up properly is not as easy as it might seem. Basically the gas strut is the same force regardless, but you adjust the angle that force is applied at and how much leverage the strut applies to the tab with a slotted mounting bracket on both the transom and the tab ends.
I found that I wanted alot less force than the instructions implied. Otherwise the tab never reached level with the water and added drag.
I would sea trial the boat for awhile with the console moved aft before deciding on a "solution" or adding these. On a 6.5m boat, especially one where the load might change alot for different activities (zooming around vs water skiing vs camping vs diving etc) you may decide that electric or hydraulic powered adjustable trim tabs are a better choice.
I've got them on my SR4 and they've stabilized it re rolling. Reckon I had the boat set up for them by chance because no loss of top speed, just better stability and quicker to pop up onto plane.
they work greaton my avon sr 5.4, pops on plane instantly, really tightens up the boat, dont think i lose any top speed, well worth the money, though i still like the feel of my boat without them, feels like its a little untamed and ready to bite you, i miss that.
