I've only had this for a couple of weeks so cant testify for its durability but so far, I couldnt be happier with this unit. It does everything I want accept have a DSLR camera option (which would have been nice). So far havent noticed any loss in the all-round abilities of the recorder, tried it with both Field recordings and with music and its done the job very well, though it also depends on the mics one uses too. I love the multitrack feature. Navigation is pretty straight forward too, which is a big plus for instruction-phobes like me.
Coming back to this after some more usage, the only issue I've struck with the unit is the touch screen control. Its small and sometimes takes a few attempts before it picks up the touch of my fingers. Maybe that's the fault of the hard worn calluses on the ends of my fingers after years of playing guitars but it can be annoying when you just want to set things up and get to work!
Now several months in after first buying this unit and still very happy with it, in general. However, the touchscreen is a real pain to make fine adjustments to volume, etc. So dont expect to do much on that. Also, strange thing seems to happen when I have it plugged in via usb to the mains supply and I connect a phantom large diaphram mic as well as any other phantom 48v mic - seems that the large diaphram drains a little too much power sometimes and the H8 just shuts down unexpectedly. Lost some work that way.
Another con is the USB power connection. Like all these damned usb connections, the one on the H8 is quite easy to damage. Fortunately, I can still power it and connect it to my computer but I do have to angle the cable now as the connection has been worn through usage over the months since I got this unit. While I am still discovering just what the H8 can do, it is disappointing that the people who design these things insist on putting stupid ports that are susceptible to breakage or wear.