"Given your apparent tastes in headphone styles, I'd recommend something like the HD25-1s or the V-Moda M80s, which are both excellent portables, as well as kind of stylish. The Phiaton MS400s could work as well." would the hd558s or hd598s be suitable for my tastes as well?
To be honest, your requirements are pretty strict, and you've only got a few choices. The closest I can think of is the Senn PX360BT (http://www.amazon.com/Sennheiser-PX-360-BT-Collapsible/dp/B003V9RWGW/ref=pd_cp_e_0), but it's bluetooth, and I'm not sure if that has a delay or not It can also be used wired, however, which does fit that req. Something like the Senn RS series will not work, because AFAIK, they're all open. I also don't know if there's any headphones that will be comfortable for 24 hours straight.
Honestly, I don't know a whole lot about amps and DACs, so you might be better off asking in the dac/amp forum. However, I know Fiio makes some good budget DACs, and the ones you mentioned have also gotten rave reviews.
The short answer is no. The Pro700 is mostly bassier than the M50s, so if you don't want that, I'd stick with the M50s. Also, i don't know where you live or where you're getting your headphones, but on Amazon (US), the 780s are only like $151, which is the same or less than the DJ1Pros.
Probably the 600, as it's supposed to have a bit more treble presence.
Given your apparent tastes in headphone styles, I'd recommend something like the HD25-1s or the V-Moda M80s, which are both excellent portables, as well as kind of stylish. The Phiaton MS400s could work as well.
If you're trying to tune someone out or use them at work, I think closed cans will work better.
Try the Koss DJ100 and the Creative Aurvana Lives. Closed cans in general leak very little sound, so there shouldn't be much of a problem.
Sorry, I must have missed it. Can you repost it?
Just FYI, surround sound in headphones will never give you true surround sound, as no matter what you feed it, it will only have 2 drivers. However, some people have reported having some nice results with Dolby Headphone surround sound, so maybe go ask in the Dolby Headphone thread? I honestly can't tell you any more than that.
Definitely the HD558s. THe PRO700MK2s are quite bass-heavy.
Maybe add the Ultrasone HFI580/780s. Do you have any particular preferences for form factor or amping? That will help eliminate some.
I'd say the 600, simply because of an increased treble presence. For more specific comparisons, look around for a thread or comparative review dedicated to the HD6XX series.
What kind of sound are you looking for? As in, what did you ike about the M50s and what didn't you like? I also have not heard a lot about the A- series, other than that they sound worse than the AD-series.
The obvious alternative to the beats is the M80s, but the LP2s have more bass.