I have had one about 6 months now. I really like it. It's easy to use. I am very, very pleased with it. I would say though that there are a couple of issues which if I was to redesign it I would take into account:
1. Bearing in mind it's designed for you to be able to tow it to where the timber is, and that will usualy be in a forest or woodland, the ground clearance is ridiculously low - about 6 " at best! Even on forest roads, if the centre is high I have to drive to one side to prevent it from grounding. Again, when reversing it into position, the rear is so low that it will catch on even the slightest rise or lump in the ground. Time and again it hits the ground while I'm moving it along forest roads or off the road onto grass.
2. Rear lights -- you WILL break these as they are very nice looking design, but so low that the bar catches the ground. Could also be improved by some guard bars over them. The metal around them is very thin and with catching on the ground mine got broken within a month and I now hang a light bar on the back when going on the road. A shame as the design looks really nice - just not practical (unless you never take it onto grass or a rough road, in which case it is fine).
3. Because you tow it from the "front" that means you can't park it directly to load into a trailer, so you have to put the machine in position first, then reverse your tailer. A minor issue, but since I generally tow my trailer to where the machine is (in a forest) , it means I have to drop the trailer off, pick up the machine and move it into position, then hook my trailer back up again to position it in front of the machine. If the machine was towed from the other end, I'd not need to carry out the second trailer movement. A minor issue, but it all adds time during the working day.
Having said these things, I think the machine is brilliant (though not cheap!) and I'm very pleased indeed that I now have one.