So I recently ordered an HD 800S which I'm still waiting in mail. So I decided to look around for the best AMP/DAC combo around Head-Fi but I still couldn't find the right one for specific "Sennheiser HD 800S" under $1000 USD. I can go over a little bit up to $1,200 but nothing more. I heard...

What differences can I expect between the two? I know that 360 Pro is closed design (Meaning no one can hear my music or whatsoever). While HD 518 is Open. (Meaning everyone may be able to hear my music) Would I get more bass?, better Mids and Highs? and better soundstage? What else is the...