that's one thing I'm concerned about. The logic of going with the Zapco amps was this...
I know it's a quality amp and for the money the 500.1 made sense. The 1000.4 was a little pricey even on sale for $750 through an authorized dealer but I said "what the hell". I think I'll be happy with the amps.
As far as the Crossfire, I'm not famaliar with them other than what I've seen at the dealer. For the interior I had considered going with Polk, Focal, Diamond Audio, Wetsounds new 6.5 co-axial, and a few others. I was able to hear them next to some slightly more expensive Diamnod Audio speakers and the sound was very slightly smoother on the Diamond Audio. If they were going in a car I would probably be going with Focal or Dynaudio.
For the sub, I didn't even consider the Crossfire until recently. I did listen to the JL W7 and W6, preferred the sound of the W6. I couldn't hear the Image Dynamics IDMAX because the dealer didn't have them set up and wasn't willing to do it. Like I said, very poor. They didn't care if I bought it or not. After trying to contact ID directly and not getting a repsonse I said "screw it". If there was a problem I would run into hell with them.
I'm usually a SQ freak but I guess given the open air nature of a boat, I put more emphasis on the amps than the speakers. You could argue by that logic that I should have just bought the most powerfull amp I could regardless of it's quality. What really drove me to the Zapco 1000.4 was that it will be pushing Wetsounds tower speakers. The Crossfire amp carries a 7-year warranty but just didn't have the juice. If I buy 2 pairs of Wetsounds the 1000.4 will be powering them exclusivily.
I've thought about going with the JL 10W6 sub over the Crossfire BMF but without hearing them side by side I couldn't tell. The BMF actaully sounded pretty good. I rationalized that if I don't like it it will go in my wife's car.
I asked my dealer if he thought I should go with the Diamond Audio D6 sub intead of the Crossfire and he said "no". He carries both but didn't have the D6 hooked up for me to listen to at the time. I do think he's an honest, competent guy which is why he's doing the install. I'm not sure our expectation levels are the same though.