Happy with mine!
Mine has twin Yanmars, and though that model engine has a great reputation, I still wish I had a single with bow thruster. That said, do a quick check online - especially boatdiesel.com regarding the 6 cylinder Yanmar in the one you're looking at. Most 6 cylinder Yanmars are fine, though there is one model that i recall with a poor rep.
The swim platform "box" on most have been fixed by now. Originally were a bolt on that were foam filled and leaked - eventually saturating and deteriorating the foam. Plenty of info on line. Nothing terminal with that issue. Probably already fixed. Actually, not sure if it was still an issue with 2003's.
Other than that, no real "gotchas" to watch out for. Just usual boat stuff that any good inspector would be looking for on all surveys.
She's kind of a jack of all trades, master of none. Just a good all around boat. I refer to mine as an SUV. Pretty versatile. Pretty good value for the dollar. Decent quality at its design price point.
PM if you have any questions. I always consider myself a rookie, but happy to share any knowledge I've gleaned. Also, there's a Yahoo group for Mainships that you can pick up some info on. If you can deal with the clunkiness of those forums.