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.
It was only LotA that was 2/2/4. Syrcus and above was 1/2/5 from the outset.

And that's a contributor, but not the only one. Despite LotA getting changed to 1/2/5, it's still slower than Syrcus, for instance.

Void Ark is as fast as ST and faster than LotA. People that are gear scumming are just trying to avoid Orbonne.
The problem with including Void Ark is that you'll also be including WoD, which isn't outgeared *quite* as badly, not to mention people still manage to fail at Angra Mainyu or chaining Cerberus somehow even nowadays.

Everything after Void Ark, even if it is still easy, is still slower.