Too bad. I had a 2008 Jayco with the Duramax engine. Tons of power, very dependable. The engine in the unit you looked at was a very good engine. I would travel in southern Oregon over the passes and recall chuckling when other class c coaches would go by me on the flats but as soon as we hit the passes, I'd have to pass them. The power was simply superior to any V-10 when it came to hills. The coach itself was a top notch coach with very little issues. The only reason we got rid of it was to move to a class A DP.
Maintenance on diesels is no big deal. A bit more expensive because of larger oil pans, maybe. As far as fuel filters, I think the only reason someone would tell you to carry a spare was so that you had one if it clogged while traveling (never had it happen to me) and the po-dunk town didn't have one. If you change your filters on the scheduled maintenance periods and performed routine maintenance, the diesel engine would far outlast gasoline engines.
2007 42' Country Coach Intrigue #12149 CAT C-13, 2014 SRX, Roadmaster Sterling, SMI AirForceOne
FMCA, Good Sam, CCFI, CCI, NWCC