I purchased my DK55c used and haven't accumulated the hours I thought I would but my experience has been wonderful. I would characterize the 55 as top of the line compact tractor. I had a Mahindra 6000 prior which I would characterize as a utility category tractor.
I am using it mostly to maintain and improve a family farm. This involves bush hogging/clearing, loader work(I have a Rhino loader and versatech grapple attachment), will be spraying in a few weeks, and hope to put a recently purchased disc to some use as well.
I'm impressed with the layout of the controls, the linked lower 3pt arms(adjustable), the 3pt control from outside the tractor, the comfort of the cab, the economical operation(2 liter turbo). I pull a 7' bush hog and it seems to do fine, it's also a good counter weight to the grapple attachment.
Only issue was a transmission linkage that jammed after the warranty expired, but was covered by the manufacturer. I have a great dealer in Vale, NC as well.
Feel free to contact me with specific questions. These are great tractors, I'd love to move up to one of the newer larger Kiotis but just can't justify doing so at this time.