For the first 5 minutes of listening to the HD700's I couldn't stand them and I wasn't sure why. I've owned them before and I did like them. I was afraid that I had been spoiled from having the HD800's and 650's, it turns out the previous owner had the Right Wire plugged into the left ear cup and the Left wire plugged into the right ear cup. I was listening to Hotel California and I was like, the instruments don't sound like they are coming out of the right places... Sure enough, the person prior to me had them plugged in wrong LOL.
At this point, the HD650 is wonderfully musical, they do a great job making all kinds of music sound great but their comfort is horrible, their sound stage is mediocre and they don't have the greatest positional accuracy. At this point the 650's are falling far behind in the other 2 headphones, BUT their price per performance in incredible. I paid $196 for the HD650's after tax and shipping. That is an insane deal that probably wont be had again. I paid $388 after tax and shipping for the HD700's, also a great deal.
I am thankful I have a few more days to figure this out, right now though here is my breakdown:
HD800 - Best overall sound, the headphones are a little big and loose on my head and and sometimes too revealing, making poorly recorded music sound worse. Also they are over $700 more then the HD700. 9/10 Gaming, not as immersive as other headphones.
HD700 - Comfortable, left ear just touches inside cup and causes some discomfort. Slightly bassier sound, treble peak is a little annoying, less revealing then the HD800's, less sound stage. $388 is amazing for the sound! 9.5/10 Gaming, slightly more bass = more immersion.
HD650 - Veiled sound, more intimate then the other 2, less positional accuracy but overall more musical then both the 700/800.. Hot and clampy, can't wear all day, 7/10 for gaming, immersive and fun but average accuracy especially in the rear and smaller stage. If this was for music listening only I'd rate the headphone a 9/10.. Little more sparkle in the treble and it would be the perfect sounding headphone for me personally for music, though it still have a comfort issue.
Thanks for your time guys, will post my final decision tomorrow or Monday.