I have had these amps together with the Doge 8 preamp and the Doge 6 cd player since December 2013 (more than a year and 3 months), bought them directly from China through Mark. (I live in Israel).
At first, the Amps with the original tubes sounded quite crappy to my ears. I changed all(!) tubes to NOS, including the 211 to GE. That last change was critical to the quality of the sound and made the most improvement. Overall the sound is VERY good, in my view comparable to almost anything out there with the usual trade-offs (like when you use low watt amps you will get less distortion but smaller sound-stage etc. ). My speakers are moded Klipsch La Scala and I use the lower negative feedback option on the Doge (but you will get much more dynamics on the high NF option).
From my experience these amps are very sensitive to the kind of cables you use (mine started to really sing only after I switched to an expensive MIT IC). Then I could experience the Nirvana I was looking for.
As for the Doge 8, don't dare using its MC input stage. Its the worst I ever heard. If you have a MC cartridge, use the MM with either a SUT or head amp. Again, change all tubes to NOS.
The CD 6 is also amazing, very recommended at its price.
As for service, don't expect what you get in the US, but the saving in costs makes up for that. I have bought many audio components in my 30 years in audio and this was the best deal, no doubt about it. Will it last 30 years or more like an an old McIntosh or Leak? I doubt it, but what current production amps will?