How is the 5000 series compared to the 4000....

Hello folks,

I bought this graphics card http://www.newegg.com/Product/Product.aspx?Item=N82E16814102795 close to 2 years ago. It is starting to fail a bit, and not handling multiple monitors very well. And when I can finally get the computer to boot with it, It blue screens my almost new windows 7 installation due to heat issues. The CPU and Mother board are running cool according to my tests, but the Graphics card is always burning hot. So I am deciding on a different card.

I'd like to be able run World of Warcraft in max settings. (like I always have). I am a Web Designer, and currently rock 2 24 inch monitors at 1920 x 1200 resolution. I would like to have near what I had before (1gb memory ram and 256bits I would like to only spend about $130 - $150.

My question is, now that the 5000 series is out, how does it match up with the card that I have?

I'm looking at this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102873

this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814129146

this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814129153

and finally, this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150467

How does the news 5000 series stack up against the old 4870 series? Can I get the same push from a 5770 that I could from my 4870?

Advice? Oppinions?