Picked one up mostly due to an interesting feature set. I've had good experience with RME gear being technically impeccable, but falling a bit short in listening tests. The ADI-2 Pro was intended to be an office rig, but I lug it to and fro work, it's that good. Ended up buying one of the limited Anniversary Editions, cuz it's black and has moar pretty.
It runs my HD800 balanced with 6x OPA1688 chips pre channel. Sounds as good or better as I've heard any HD800 perform. It also does 5 band PEQ which makes HD800's actually listenable. For my Equator Q12 I use the back XLR's and intend to hook up a MiniDSP via optical to integrate two custom 15" subs.
Anyho - check this thing out, if you're looking for an interesting source unit. Cheerio.
P.S. Nudie (almost Gilmore sized)