Hi Lat26, we have a 2013 Monaco Diplomat and have been really happy with it, they have been great on any warranty issues, and the Maxxforce Engine has worked as it is suppose to.
Here's a link to a thread of mine on the Maxxforce 10 you'll especially want to read OutNArounds comment on page 2. He has some excellent advice on this engine. Which should help in making a decision.
http://www.irv2.com/forums/f122/firs...0-a-177398.htm
Being a leftover 2012 you should be able to get one heck of a good price on it.
There's a lot of good info in the Maxxforce Engine section too. You can find that here.
http://www.irv2.com/forums/f122/