The main difference I could find between the 2014 and 2015 was the trim and awning color, which on the 2015 is dark brown instead of white. I think the graphics have changed as well. The 2015 has LED interior lighting. Not sure if the 2014 or 2013 has this. It also has the LED exterior lighting strip, but I think that was also on the 2014.
We did not get a shower surround, just the wall paper in the tub/shower area. I have seen photos of 213's from various year with the shower surround, and others without.
Also, no black tank flush. Not sure if any model years had that.
John, Heidi, with Big Papi & Venus (Cocker Spaniels)
2012 Nissan Pathfinder SV 4X4
Hensley Cub WDH, Tekonsha Primus IQ