I have a RX6010 and it is a great tractor, The power reverser works very good and the main (4 speed) transmission shifts easily, the range transmission is a little clunky and the detents between medium and neutral take a little getting use to but not a issue really, there is just some room for improvement there.
The engine is powerful, Mine is not tier 4 so its old school simple but it also has some smoke on cold starts, very easy on fuel, cab is very comfortable from 90 above to -30 below weather we get up in Minnesota, here are a couple short videos if you want to see it in action.
https://www.youtube.com/watch?v=bvtBcjdNNj0
https://www.youtube.com/watch?v=215GYQMQDxo
https://www.youtube.com/watch?v=KJk3IIkbKvg
https://www.youtube.com/watch?v=isWPJLgjaUI