As comfortable and great as these headphones are, wearing them still fatigues me and I just don't enjoy having them on. I really enjoy speakers.
In my college dorm, I had TCA WAF-1s with a TCA Gizmo. I've upgraded my amp and purchased an inexpensive DAC + Energy 12" sub since then, but I'm very happy. You can spend a few hundred and have a really nice setup; after that point, you'll see marginal improvements but with huge leaps in prices.
By the way, don't your k550s also leak? However I adjust the pads, it still feels like everyone could hear what I'm listening. Never tested them by making someone else wear them but they feel not tight enough so never bothered to bring them to the workplace. I'm working in a shared office, so it really matters. Currently I'm using my M50s but k550s are so much better and if it's not as bad as I thought, I'd definitely use them instead.
There's a decent noise floor in my office, and most of the other people use headphones. Even for the ones that don't, there's enough that my music isn't really audible. I'm also pretty vigilant about keeping my volume low, mostly for my own health.