Don't know the boat or the dealer but you are smart to check things out in advance. I would maybe not be so concerned about negative comments (you can't make EVERYONE happy) if you don't plan to use them on an ongoing basis for service, storage etc.
Also, things change. The dealer I originally purchased from could not have made the deal better or done a better job at service in the first couple of years. The last service visit resulted in them giving me a dirty boat plus losing my keys and not responding to repeated requests to rectify, so I decided not to do anymore business with them.