Just to introduce myself, I'm a level 76 (maybe 77 by the time you read this thread) Frost Death Knight. My goal is to get to level 80 and tank heroics and maybe raids someday. Right now I'm putting together a gear list made up of mostly stuff from quests, world drops, and BoE crafted gear. There's really only been one debatable choice so far, and that is the choice between Claymore of The Prophet and Titansteel Destroyer.
The Destroyer's slower speed will result in larger Obliterate hits, but the presence of haste and more hit rating on the Claymore make make up for the lost threat.
The Claymore was ranked higher at lootrank.com when I used the template they have setup, but I just wanted too know what 'the pros' thought, or what other prospective DK tanks are taking.

Quick Footnote, Claymore of the Prophet is also known as Greatsword of the Sin'Dorei. It is a reward from the Argent Tournament.