So I recently got a pair of Senn HD4.40 Bt's since I was in the market for a pair of BT headphones, and not only am I a big fan of the classic Sennheiser Sound and build quality, but they were also right in my price range!! When they finally arrived, I was blown out of the water. See, I'm new to the Headphone scene. My experience boils down to my Dad having a pair of Sennheiser's at home (the HD 435 or something), as well as a pair of Grado SR-80e's. On my end, I had a pair of Klipsch x11i's that I used as my daily drivers until they severed at the jack. So since then I've been using my gaming headset, a Polk Melee. Its decent and delivers some punch in the low range, but the mids are hardly there and the highs have no presence. When i got the 4.40BT's I was stunned. They had the classic Sennheiser Sound veiling the highs, the mids were present and clear, and the lows blew me out of the water. Being a bass player, i really like my lows and i was shocked when the 4.40BT's not only had an extreme plethora of bass, but they managed to do it without muddying the mix in the slightest. Now all of that is great, but they don't fit all to well over my ears. My ears kind of fit into the cans instead of the cans resting around my ears, and this can lead to some discomfort after a few hours of listening. Now this brings me to the PXC-550's. As i understand it, the PXC-550's are Sennheiser's premiere BT headphones. But, seeing as how they are about $100-150 more expensive than the 4.40's I really wanna know if, when I've got the money, I should upgrade the the 550's. The main thing that I really love about the 4.40's is their incredible sound quality, especially considering the amount of bass put through them. The main thing is... will they sound better than the 4.40's WITH a similar amount of Bass?