Hrm? I have... there really is no difference. With PBR and other American Adjunct Beers ( http://beeradvocate.com/lists/style/38 ) It has little to to about taste and everything to do with not wanting to buy from the 3 industrial leaders that own 90% of the market.
If you're on the east coast, you guys should try Yuengling. It's easily one of the best cheap* beers out there.
* < $1/bottle
I'll second that. Also their "black and tan" is fantastic if you want to go slightly more expensive.
West-coast guy here, I'd never heard of Yuengling till I visited Virginia Beach. And I'll agree, for a "swill" beer, that's some pretty good stuff you've got going on there!
Those beers may all hover around the same quality, but I don't think a blind taste test could work at all with those beers (one way or the other.) They are all rather distinct in their refreshing mediocrity (Coors is significantly more mild than PBR (hard to say if that is in a good way, or a bad way), and Rolling Rock has a distinct "corn" flavour.) Anyone who drinks a lot of those beers is going to be able to pick out which is which, at which point the taste test would no longer be blind.