I've owned a DK35 for over 5 years. I have over 1200 hours on it and it has never failed me with one exception and that was when I got a bad batch of fuel, but that's not the Kioti's fault.
I have 87 acres of hay fields and mixed northern hardwood forest. I've used it to haul logs, plow fields, bushhog 20 acres of field, haul gravel to repair roads, and many other duties. By the way it has a 66" bucket and I can load it full with gravel and lift it with no problem.
It uses about 3/4 of a gallon of fuel per hour of operation and has been very dependable, it gets to -10 or more here and it always starts with just 2 cycles of the glow plugs.
I've not found the need to wish I had the DK40, I know many here will tell you that more horsepower is always better but as the old farmer down the road always said "Why feed 2 horses when you only need one to do the job."