[Pocket]

typon77, you're missing OO (as you mentioned) and Checks and Counters

Focus Blast > Superpower, imo. Superpower can come in handy against TTar on the Specs set, but it can't 2HKO Blissey / Chansey, so it's not worth it.

Agreeing with nyczxjay that Tailwind should be slashed in the fourth slot instead of Sleep Talk. Rain Dance is also a good choice that may replace HP Ice, a seldomly used move.

AC mention Expert Belt; HP Ground to hit Jirachi, Heatran, and Magnezone super-effectively without the worry of missing.

Definitely add Acrobatics set; unlike Tornadus-T, it actually has good Attack to make for a deadly physical Acrobatics spammer.

move 1: Acrobatics
move 2: Superpower
move 3: Taunt
move 4: Tailwind / Bulk Up / U-turn
item: Flying Gem
nature: Jolly

Tailwind is super-clutch, while a single Bulk Up can would make Tornadus almost unstoppable. In actual practice, I did not really find a chance to set up, though.

AC mention Heat Wave and Naive Nature for this Acrobatics set to bust through Steel-types.

I like your Overview - I think it's worth mentioning that it's lower base Speed adds more mons that checks it, namely Scarf Tar, Starmie, Tornadus-T, and even opposing Dugtrio.

Also emphasize that lack of Regenerator makes Tornadus far more vulnerable to SR, making its LO set far more unwieldy.