Don't mean to bump the thread but I figure it might be useful to others who are between the GR07 MK2 and UE900 or similar headphones at those price points/categories.
I am very happy with my UE900, especially since it was discounted 100 USD because of the "dented box" which by the way must merely a somewhat dusty/old looking box with the tiniest rip in one of the pieces of cardboard.
I don't know audiophile terminology very well but the sound is substantially better mixed than with the GR07, which didn't sound so much analytical but less emotional (I don't think its mids were as good but I had some fit issues). The GR07's also had some slightly deeper bass but I don't think recovered from it quickly enough. For instance, in the last seconds of
Animal Bones by Protest the Hero (4:00 mark), there is this awesome bass line that on the GR07 sounds like it's somewhat separated/delayed in that measure or maybe the rest of the instruments in that measure are drowned out/not as high. On the UE900, the bass line loses some of its awesome deep sound but is still somewhat accented and sounds more on time.
My only complaints so far are only related to build quality. The blue vi cable (mic + volume and play controls) is broken; on many sources it likes to cut out sound to the right bud. My co-workers vi cable also has this issue. I'm going to be RMAing mine shortly. Also the arrows on the cables ends that indicate whether they are for the left channel or right channel can wear away if you touch/rub them. I'm not sure if this has improved with new batches of cables. Finally pulling the buds out from the cables can be hit or miss. A lot of people say it's stupid easy to do; for me this is only true for the right bud and not true at all for the left bud. It takes some pressure/strength to pull it, almost enough that you can imagine snapping your cable-to-bud connector into pieces.
HOWEVER the GR07 build quality, while good, possessed some massive user experience banes. The entire in-ear piece pivoted in two axes like crazy whereas the UE 900's is locked to only swivel along one axis. Furthermore the GR07 cable untangling was the biggest exercise in frustration I've ever experienced with any audio equipment I've ever owned. The UE 900 braided cables don't tangle anywhere near as much but don't retain memory either.
For reference I'm a punk (from Black Flag to Strung Out, Pennywise to Refused, Bad Religion to A Wilhelm Scream) and highly technical metal listener (Protest the Hero, Soilwork, Periphery, Meshuggah, The Human Abstract) who also frequently listens to more traditional metal bands such as Lamb of God, Pantera, Judas Priest, etc.
Hope that helps anyone who may run across this thread in the future. It's too easy to get lost in the UE 900 Appreciation Thread.