I've had my ATH-AD700 for a couple years now. I use the mostly for PC gaming with my Asus Xonar DG for dolby (when applicable) and eq'ing. I do listen to some music on them, but most of my music is heard through IEMs/iPod at work or on travel. I Think the AD700 sound very nice with the bottom end ramped up from slightly starting at 250hz to up 10db at 30hz. Not that I'm a bass head, but I enjoy impact and bass extension. They also sound great without the eq on acoustic/instrumental music.
During Xmas I acquired some best buy gift cards and can't figure out what to do with them. This got me thinking, should I try something more Sennheiser. I generally like warm/bass strong sounding audio equipment, Senn's warm laid back sound seems like it might fit the bill.
So, is there any reason that Sennheisers would be better for me. I threw the closed HD380 into the mix for some variety (and for travel and work)