Actually, I suddenly think I know why the CT raids are going so much faster, though I could be wrong. The raid-wide DPS totals are higher now than they were, and not just because of ilevel creep. Before, it was 2tanks/2healers/4DPS, and now it's 1Tank/2healers/5DPS. We literally have more damage now than we could have had then, even with matching item levels.