Very happy with the purchase.
Currently, I am just using basic PCM2704 USB DAC (waiting for M8 to arrive), but amp works and sounds fine.
It drives DT770/250Ohm fine (DT770 goes on HIGH gain output, of course), and Fidelio X2 is also very easily driven. Didn't bother trying anything else on it, I bought it to listen music not to test headphones.
It looks and feels like a quality product. We'll see how it handles the test of time.
I can't say I notice any difference between Magni 2U and VA2 in audio, both do the job very good and for $80 (plus shipping) that I paid for it, I am extremely satisfied.
I didn't know if I am going to like the volume control, but I am now in love with it, since it is extremely simple/easy to change the volume with a touch of a finger (while 'holding' amp with other finger), and since amp is sitting below the monitor this setup is perfect for my needs.
I will leave the 'highs are crisp, lows are subtle' type of comments to someone else, I just love listening to music.