I've been in kind of a similar situation as you. However, I have not tried the big flagships, and only owned one pair of Planar Magnetics. But other than that, over the years I've owned probably around 30-50 headphones total. Never really found that exact sound I was looking for. Been happy with a lot, but. There was always something missing. My most expensive cans was around 400 dollars. All the ones I've owned have been over-ear and almost all open-back. I remember trying on-ear a long time ago, and I swore never again. I guess they had too much clamp. Then however, because of all the rave. I decided to try the KSC75. My mind was blown away regarding the sound quality for so little. The sound signature I already knew wasn't to my taste, but the sound quality for such a low cost. I was hugely impressed. I've always heard about the Porta Pros for years. But them being on-ear, I've never cared to try them. Trying the KSC75 changed that. People said they fdidn't find them uncomfortab le, so I took the plunge. I'm so happy I did. The sound is what I've been looking for all along. I now have 3 pair and 2 KPH30i's. The Porta Pros being my preffered because I like the comfort better, but they sound very much alike. Awesome cans! I always say to people instead of starting out getting a pair of HD600's or something like that, they should try one of the 4 amazing Koss headphones they make for a cheap price, and see if they are happy with that. I sold everything else, and only have Koss headphones now, and Monk Plus for train rides/bus, since they don't really leak sound compared to the Porta Pros.