Alright, so the current pair of cans I own are Bose's QC15 cans, for those of you who don't already know, and basically I'm in pursuit of something bigger and better that also costs less. I'm considering Grado's SR60i or maybe Sennheiser's HD518 or 558. I'm going to try and test any pair of headphones before I get them, but the aforementioned cans are kinda my hypothetical wish list at this point. How would one compare the QC15's to the SR60i's or the HD5x8's, in terms of sound signature and just stuff like that? I'm aware that I'm probably asking you to compare apples to oranges or whatever, and I apologize for posting fairly incessantly about this stuff. But any help would be great!