Is a Radeon 5670 good for Xfire?

I'm looking at getting a pair of XFX Radeon 5670 1 gb DDR5 cards and I was wondering if anyone around here has any experience running xfire with that card. The AMD and XFX websites say that it does support xfire and I know my mobo does, so I just wanted to know if anyone has had any experience with this card, either good or bad.

For less than or equal to the price of two 5670s you can get a single 6770 or 6790 that will blow the 5670s away. It will be much faster, last longer, and you can add another one down for crossfire down the road. Much better value. They are like $100-120

http://www.newegg.com/Product/Product.aspx?Item=N82E16814131397
$99 after rebate

I would stick away from 6770s, from what I've read/seen they appear to be a gutted version of the 5770 (and perform worse than it).

hmmmm. My plan was to buy one 6670 and then add a second because I'm on a pretty strict budget right now.