We used to trade fairly often, as newer features we wanted kept showing up in the market.
In 2007 we ordered our current MH and we've stopped shopping.
For us, all of the features finally came together in a MH that fit our budget;
4 slides
Full body paint
Big, high torque diesel
Full pass-thru basement
Comfort Drive
Looking at today's MHs I see some really nice new "stuff" but nothing real revolutionary that makes us want to buy another.
So for us, the 2008 model year is when it all finally came together, and our current MH will probably take us into our Golden Years. :B