I did the conversion on my 85 38 Cigarette and love the drives.
I did have a problem getting on plane with the raised X-dimension.
With My trs's I could turn 25 Mirages 5100 Rpm. with 550hp each. I usually ran 24 Hydromotives at 5000rpm's
I could barely get the boat on plane if it was rough out with 24 Hydro' and 26 Bravo's Until I put a 1"spacer and lowered the drive back down. Then it would jump on plane and the prop was more efficient. The raised x did not help my boat at all.
I took the spacers out this year and ran a 25 P5X the boat came on plane easily in any kind of water but was not as efficient as they were with the spacers.
Next year I am putting the spacer back in so I can run the 4 blade or the 5 blade props.