I had a 6000 and sold it when I got the DK55c. The DK55 is shorter and so it is a little more choppy going over wash boardie terrain. I also have the R4s on the Kioti which don't absorb the bumps as well. I'm assuming the 6500 will ride the same as the 6000 which was very good. The 6500 has the quick attach bucket which was the only thing I missed on the 6000( I didn't realize it is fairly inexpensive to convert the ML264 to quick attach).
What I like about the DK - very easy to service. Smooth running, Cab, I think it is 5000'lbs so it is significantly lighter than the 00 series, but it still will do good work. I have a Kioti dealer close by so that was a motivation.
I like both for different reasons and will keep which ever I don't sell.
It took me a long time to find my 6000 and don't see many on the market. I bought the 6500 with that in mind and it is currently listed in the classifieds. I would sell either but I just added a grapple to the DK so I'd rather keep it until I can get a few things cleaned up.