James I can't say EXACTLY what your boat will do as mine is a ProSport (225SS 14.5" hyd plate) but the two are close enough that I can't see them being entirely different. I tried an HP4 on my boat once and it SUCKED! I had a 29" RE3 that cracked after one summer and while talking with John Mazar I asked about an HP4 and he said that at that time he hadn't had enough of them on ProSports to know exactly what they would do (this would've been 1999) so he built me a 28" HP4 and sent it too me. Did I mention it SUCKED? The holeshot was fine and up too about 60 it was ok, after that the prop simply wouldn't carry the boat. EVERYTIME it hit 80-81 it would simply blowout. It also never would lift the hull properly, the boat would run flat and "mushy" feeling. I tried it several jackplate heights and it wouldn't matter, same result.
I called him back and he said that he guessed that prop was more for traditional hulls he reckoned. So I sent it back and he built me a 28" RE3 and I ran that for another summer and then it cracked as well. So as good as the REs run I just refuse to run them anymore because they seem to brittle. The HPs seem like a "Trophy copy" just looking at them, but they sure don't run like em.
As for the Hydromotive, if you are talking about the Quad IV OT then I think they are the best all around prop on the market. On my rig it ran 91gps with a heavy two man load (28" Quad IV OT) and for comparison Glenn Reynolds ran it by himself empty of fishing equipment (still had troller, batteries, fishin seats, fuel etc..) 94 with his own ET. The Quad IV also had so much stern lift that it made the boat feel like it was 5' longer with the way it improved ride quality over a stock Trophy. The exact same 2 man load (same day, about 30mins apart) I ran 91 with the QuadIV I ran 88.8gps with a stock 27" Trophy.
The only downside with the Quad IV was holeshot, but that prop wasn't relieved enough my SS engine (they have poor bottom end) and Todd told me he can now drill dual ventholes on each blade so I will eventually be getting a QuadIV to replace my Trophy and other props. The Quad IV has INCREDIBLE mid range, you can feel the punch and acceleration. The Trophy you just mash the gas and look at your watch! :roll: The Quad IV is also beefier and a very durable prop yet still ran like it did.
You mentioned a 25" Trophy, holeshot wise practically any thru and over/thru hub of 27" or greater is gonna be hardpressed to beat the bottom end of a 25"er. It's just hard to get it "all". To get that few extra mph on top you typically have to give up a few seconds on the bottom end and vice versa...
I haven't run a worked 27" Trophy, but for that kind of money you can get a Quad IV and that's my pick, so it's your choice. Just STAY AWAY from the HP4, if you have a deal with Mazco then go with either an RE3 or RE4 and just be ready to replace it shortly because they DO crack. If you go the full overhub route then look at the ETs, cut choppers, cut SRXs etc...
Good luck,
RA