I purchased these headphones a little over a year ago (alongside a Schiit Magni), and I have to say that I have trouble imagining a better purchase for the money. I'm still blown away by the sheer clarity of everything that I hear, from all genres of music, at all sound levels. I put the velours in over the stock pads after about 2 days, and never looked back.
My biggest complaint comes from the build quality. The screws that attach the cables to the ear pieces are now chronically loose, and I find myself having to fiddle with them almost every time I put the headphones on to get a solid connection. The screws attaching the headband to the ear pieces have also come loose on several occasions, and when they pop out it kind of freaks me out because it feels like I just broke my $400 (now $300) piece of equipment. I'd be obliged if anyone has any suggestions concerning the loose screws, because they are the only thing that interrupt me from having a near-perfect experience.
Cables - unscrew both cables out of the headphones and turn each cable in the opposite direction you are going to screw them in (several times)....so there is a bit of tension in them once you insert into the screw hole. The tension should disappear as you screw them fully into the 400's as you are winding back the opposite way.
Gimbal screws - epoxy them in or use a dab of a medium glue. You don't want to lose those small screws whatever you do. Make sure your screwdriver fills the entire phillips cross style screw hole as various smaller screwdrivers can fit in the hole but it can shred the thread if you do.