Defense rating question!

[webbster22]

Hey guys I've been at work reading up as much as possible (converting from holydin to tankadin) and I am confused about the "cap" to a character's defense rating.

I'm gathering that 540 is the defense cap, but I have seen 689 thrown around quite a bit. I have been collecting my tank gear from TOC and tokens and should be a little above 540 when I gem and enchant everything when I get home.

My question is, I guess, is 540 all I need? Or is 689 the rating I should be shooting for? Also, Once I hit 540 or 689, which mitigation factor should I focus on? I am new to this so I apologize for my noob-ness.

Oh! One last thing... as far as gemming goes, I shouldn't need to ever gem strength, right? I should focus on stam/def/mitigation... the + block value strength offers is nice, though. Just wondering if it is more important.

Thanks!

[Grehn|Skipjack]

540 is the amount of defense skill you need to be uncrittable versus a level 83, or a raid boss. 689 is the amount of defense rating that gets you to 540 skill. Effectively, they're the same number. And no, you don't need to gem for strength.