That initial sterile sound does go away after some extensive burn in. I've had mine for 5 days now. To me, its definately an improvement over the Ref7.1 but is heaps more 'cleaner' and transparent sounding than the Ref7 and a bit more than the Ref7.1 Improvements was very noticable around bass and highs over its predicessors.
It may or may not be to your liking, if you prefer the more 'rounded' sound of the Ref7, then this may not be the dac for you. Personally, i think this is the most neutral sounding dac that Kingwa has built to date. The USB-32 chip worked very well for me. The ViA drivers installed without issues for me on Win8 Pre-release. Also installed it on my Win7 64 laptop and it did it without issues. As Kingwa said, best to configure it to run in 32bit mode and also set your choice of player (Jplay/Foobar/Jriver) to output at 32bit.
The 300hour burn in doesnt do it justice. It does need quite a bit of warm up to sound good as with all other A-GD dacs and equipment. For those who have a DI-DSP could get a I2S output that is pin compatible to be used with the Master 7.