Back in late July we toiled over a 2015 vs 2016 (before the vibration issue was really a documented problem). We chose the 2015 Greyhawk (29MV) for these reasons;
- Better negotiated price
- More room on front sofa (2015 have removable side armrests where 2016 do not - loosing 10" in width/length when making into bed)
- Front sofa has better cushion (2016 very firm)
- Don't trust early/new major upgrades on 1st year models (transmission & fiberglass roof). Wait until mid-year production for bugs to be documented and worked out (vibration issues for example)
- Countertop does not have raised splash guard on back (only a bead of silicon in corner - potential issue with water on countertop)
- No hidden hinges on cabinetry
- Did not care for cream color paint scheme vs light beige on coach exterior
- Pleated Day/Night shades on windows vs simple pull-down shades
- Frosted door window (2016 have regular clear window - no privacy or standard window shade)
Of the 2016 improvements we did like was;
- Stated increase towing capacity (though 2015 chassis is same I have read)
- Larger windows on door and in bath
- At least on our model, upgraded LED TV brands (Furrion vs Jensen) - we are having Jayco replace ours though
- Upgraded walled backsplash in kitchen
- Newer model year of course
- Upgraded digital TV antenna
I was told by Jayco that some of the changes made from one model year to the next are due to supply, competition, cost, technology and ease of assembly. Model updates are ongoing and may even change several times during model year production.