Well first things first: Merry Christmas to all, or your respective celebration!
I really appreciate all the feedback I am getting, and am enjoying reading everyones impressions. I now see why forums are so addictive ahaha.
I did some major listening the past few days. Well... Grado 325i and AKG 701 can go. Grado just seems to keep losing its value. I mean it is a 300$ can, but it just can't keep up, and has a worse soundstage than the SA5k.
AKG 701 doesn't catch my attention. Just does its job well... I guess this is good and bad.
So like I said in my post before, I am stuck with the HD 600 and the SA5K and wanting a combination of their respective strengths.
The HE-5 looks very intriguing... on par apparently with the HD 800 and ~1/3 as expensive??? seems like my kind of can...
There seem to be skeptics, but the beyer 880/600 seems to be getting a good bit of recommendation.
I am wondering if a tube amp would help with the SA5K because tubes, by nature, are warm from what I have read...
My girlfriend bought me a pair of Ultrasone Proline 750 (I chose the right girl!)... I have read some very positive reviews, but there are few. Supposedly a faster, more detailed HD 600? I would open it, but the store probably won't accept a return for "hygiene" reasons. Apparently they don't trust me to wash my hair...