I was finally able to do some testing on my board (Asus Rampage II Gene). Using latest sound-unstable I can confirm that the crashes in XFCE mixer are gone. Also, labels in alsamixer make more sense now - I have microphone plugged to the back and previously I had to enable Front Mic as an input source to for the microphone to work. Now, it works over "Rear Mic" as expected. Also, multistream playback works with "Independent HP" enabled. And yes, less controls then before ... Overall, a big improvement.
My alsa-info can be found here: http://pastebin.com/RaxrnZKK
Should I try with branch 'test/hda-gen-parser' (what is the difference, BTW?)
Anything else to test?
When can we expect patches from sound-unstable to appear in main kernel?
Thanks, Miro