Is it worth it for me to get 4-set bonus with 665 pieces?

[Ghettobeast 0]

Hey guys. My guild is having some trouble in heroic so I'm thinking that I could go normal to get some set pieces. But is it worth it?

 

My armory: http://eu.battle.net/wow/en/character/kazzak/Ghettobeast/advanced

 

I was also wondering; what is the best time to use our second potion if bloodlust is used just after the pull?

 

Thanks a lot! Have a nice day!

Edited February 20, 2015 by Ghettobeast

[Orthios 271]

Get the shoulders for the 2 set at the very least, that's the biggest upgrade out of the tier pieces.  For the 4 set, you'd have to sim the different remaining options vs what you have (legs/hands, legs/head, and hands/head), but AMR has the legs/hands as the largest upgrade between the three.