I fully endorse sending Blizzard tangible examples of the inefficiency of our tier sets. That being said, I would be very curious to see this test run with a Paladin in the generic pieces from Kara (Mantle of Abrahamis, Panzat'Thar BP etc)as opposed to the t4 pieces of shiny dung. I imagine it should follow very closely to your Paladin in warrior gear, but hard numbers are always nice.
The 'Hybrid' pieces listed in Theras tests are items like the Mantle of Abrahmis etc.
Paladin gear: T4
Hybrid gear: The random assorted pieces
Warrior gear: Warrior T4
Accoring to the spreadsheet, the hybrid gear is a mix of Crystalforge and less spell damage plate in the off slots:
[Barbed Choker of Discipline]
[Gilded Thorium Cloak]
[Bracers of the Green Fortress]
[Crystal Girdle of the Indomitable]
More tank friendly than the Paladin set, but not with the assorted plan B tank items like Irong Gauntlets of the Maiden. The stats on the spreadsheet also show the Tier4 slots to have the same stats (spell damage etc) as the Paladin gear, so I don't think it was just a naming copy/paste error.
I think I've finished up the top of the line Tier 5 sets, and have gotten some preliminary tests done on Tier 6. I don't have time for much of a summary for you (since I'm exhausted), but here is a link to the spreadsheet.
Some key points I picked out:
Tier 5 Protection Paladins are still about even keel with Arms Warriors in their own equipment, though our incoming damage curve is not susceptible to spikes making us the clear choice.
Tier 6 Protection Paladins are very competitive with comparably geared Protection Warriors, and bury Arms Warriors. Given what we know about Illidan (he's a dual wielding demon) we may yet see a Protection Paladin being the tank of choice for the final encounter in the Burning Crusade.
Modifying Ardent Defender to not be leapfroggable would make Paladins the clear tank of choice in nearly all situations, period. That's unacceptable, so we can scrap that idea.
You no longer need a Libram of Repentance in a Tier 5 suit and onwards.
Personally, I can live with that. I'm still a little burned up that the Tier 4 level of equipment involves opening up Excel every time I consider an item upgrade, but thankfully that phase will pass once you're into Serpentshrine and you can pick up items like a normal person.