Had them for 3 days, and been listening to them most hours of the day. Here are my notes. If you want the short version; Great neutral headphones, highly reccomended.
Clean sound.
Too harsh on bright recordings.
Perfect on smooth and darker recordings.
Sits really well on your head, can hurt a bit after a while, but probably only until they are fully worn in. Well made.
Not alot of low bass. So the mid bass is a bit too forward compared to the bass in full. But super clean.
Female vocals are a pleasure.
Prefer male vocals and bass/low guitar acoustics on smoother/darker headphones. Very neutral.
Haven't heard the HD650's, but I ordered the HD6XX's. Those will probably be just be up my alley, probably sounding a bit worse on dark recordings, but alot better on brighter recordings. The bright recordings + neutral phones just isn't me, makes my head hurt.
Have a good day.