I'm no expert on the 900, but when I was purchasing my 1140, differences present in the newer version included
better seats/foam/shape/comfort, more waterproof bottom
solid behind the seat... avoids pocket book from falling to ground if it slips from rear pocket.
hst transmission stops much smoother/slower
easier to get to some of the dipsticks, etc.
u joints now have grease zerks... should last much longer
Seems to me that there was more, but this is all I can recall at the moment.
Overall, these were improvements that a lot of people said were needed to improve the usability and reliability of the vehicle.