Indeed great review, sums it up pretty accurately.
I have the exact same impressions although I can comment on the amp part.
Currently I have hooked the HD800 directly to my e20 DAC.
It's hard to imagine that it will be even better when driven balanced with a GS-XMkII ....waiting..... waiting ..... waiting.
I really think that the good combo can be found with amp or dac or dac+ amp.. There're many possible way to find the good combination. The point is that finding the good combo needs time and money. Too many owners didn't take enough time with their HD800.
HD800 is for persevering people.