We bought new 2013 GT 335DS last winter. Previously owned 29 ft Winni class C with 2 slides. Really liked Wiini but just felt we needed more room. Camped about 45 nights and 2000 mi. since got GT.
First off, class A GT is night and day difference. I think GT handles better on road. leveling jacks, power awning, etc. make setting up a breeze. Love fireplace, large screen TV, power front shades. One thing on "wish list" is a larger gray water holding tank. After 3 days it becomes an issue if with out sewer hookup. Plenty of power down highway. Lots of inside storage.
As for problems and service. Hydraulic lines for jacks had bulges when we got MH and maybe some very minor issues which I took care of, no problem. Dealer took care of hydraulic lines immediately. Hope our good luck continues after warranty runs out!!
We are very happy with unit. Love floor plan. We know there are bigger and fancier units, but we are more than happy with what we have. Would defintely buy another. Can't wait for summer