The 6R140 is a slick transmission.
The other differences are model dependent. For example: The 24.1 model recently switched the way the bathroom door works (not sure if that was a 2015-2016 switch or a 2014-2015 switch). In the older models the door is a two piece folding door that, when open, combines the bathroom with the rear bedroom making for a large changing area.
The newer version of that door splits the fold so that the doors are more like a clamshell and when open the connect to the other side of the camper making just the bathroom bigger.
It is diagrammed in the floorplan: 2014:
The newer 24.1 also has some USB charger connections and a 2nd radio in the back bedroom. The TV is also larger in newer models.