Good questions, great car, but it does have its own "personality" like most do. Nothing too major though except the atx's can be fragile. Since you're not buying for a month or so, recommend digging thru these links if ya haven't done so...
http://www.mx-3.com/recalls/
http://www.mx-3.com/tsb/
Also work your way down the technical forums on this board and watch for repeating topics about troubles. Eg, the GS V6 K8 engine's distributor is a commonly required replacement and not a cheap one. Ask the owner about that. Your dream-come-true buy would be from an owner who has receipt records for anything ever done to the car.
This alldata link is for a fee based service that you register a specific car for to access great info, diagrams, part numbers etc. After you buy the MX, might wanna pony the $ for a one year membership. Then download or print all the info you can (and let the subscription run out.)
http://alldata.com/products/diy/index.html