Shield advice

[Shathus]

So I've had 2 shields,
http://www.wowhead.com/?item=31200 for instancing

http://www.wowhead.com/?item=25828 for threat/questing

I got
http://www.wowhead.com/?item=35817 from a quest last night. It's got 1000 for armor , double the block and stam of the Lichen Guard. I assume it's not worth replacing my instancing shield yet because of the lack of +def but wanted to get some thoughts.

Yah, it's an early level quest reward and I know i'll be replacing it down the line...

thanks in advance

EDIT: damn acronyms... missed this thread right below... cause that kinda answers my question, but if you still feel like responding

http://www.failsafedesign.com/maintanka ... php?t=1698