I've had two real experiences with Bose. One was with the TriPort, as a christmas gift several years ago. They were serviceable, I didn't know whether their shortcomings were because of my source (an integrated laptop soundcard), or the 'phones themselves, and I didn't really want to spend the money to find out. I'd give them about a 4.5/10 if I had to rate them. Not horrible, but it's not like they'll make your ears bleed. Sure they're muddy and muffled, but to the masses that just equates to "inoffensive". I know people who love FM radio because of the bloated bass, and understandably they loved my TriPorts alot more than I did.
The other experience was with car stereos. The Bose unit in my father's aging Nissan Pathfinder is pretty crummy, the stock unit in my Subaru sounds much better, especially after I routed an AUX port into it. The best experience I've had with Bose was in the 1984 Corvette my father used to own. It was truly one of the better sounding stereos I've heard, but it's also been a really long time since I've heard it. But compared to our Dodge Caravan of the time, the stereo had sparkle and definition (both tape units, though, neither car was exactly new). But again, this has been about a decade.