Hearing all those different phones one thing is obvious to me:
I'd be very happy with any of those set-ups!
Biggest lesson learned is to trust your own ears and opinion primarily. You can read so much about a particular phone but there's so much exaggeration, fan boyism and unjustified bashing that you never can tell until they're on your head!
I think each of the phones shined in their own ways:
The MS1s I found where very aggresive in there presentation of rock/metal, which was great fun. Mids where highly emphasized and really drove guitar riffs into my skull! More bright then I'm used to with my phones, but not overly so. Bass was not it's strongest point but still present.
The AD700 take they trophy for best price/performance, IMO. Although I did not get a very long listen with them, I thought they were extremely comfortable and had a nice airy, well balanced sound signature to them. Very Nice!
Joneeboi's frankengrado was quite the sight to behold! I though this phone sounded very much like the MS1s with a larger soundstage, thanks to the colossal GS-1000 pads. Also, more emphasis on the treble which gave some favourite tunes a different flavour. Well done, man!
K601s where a treat to listen to, for myself. Scored big points for sound stage and instrument seperation/clarity. Not nearly as clinical/cold as people make them out to be on here. Also, bass was fairly good to my taste. Quantity wasn't huge but it was definitely present and well defined.
DT990s - Although I thought these had a very good sound signature I did notice some sibilance when using them on my rig. Could be a lack of synergy or the track I was using? Not enough time to tell but otherwise a nice sounding phone.
rwaudio amps - All I can say is: how much and when can you build it? lol Seriously though, the larger amp(high gain model, I believe) sounded absolutely perfect in my chain with the 650s. I've never heard the treble sparkle so much on the 650s until now! Expect a PM...
Wish I had more time to talk with you guys. It was hard to cram everything into 3 hours! Until next time, I guess!