If DT feel they can deliver a better performance of a given song by lowering it, then I'm not opposed to it in principle. Sometimes, for most of us who don't have perfect pitch, you barely notice when a song is dropped. Other times, it is a lot more obvious. It just depends on the song. For example, when Queensryche started tuning down The Lady Wore Black in 2000 or so, it was very apparent, but it made the overall feel of the song more dark and heavy. On the other hand, I saw Tesla a couple of years ago, and they tuned down a couple of their songs (Edison's Medicine and, if I'm not mistaken, Hang Tough), and both of those just felt like all life was sucked out of them.