6950 or 6970 in crossfire?

[me2622b]

Hi,
I got the money together to do a GPU upgrade and I wanted some advice on which set of cards to buy. two 6950's in crossfire or two 6970's in crossfire. Let me tell you a little bit about my system.
Core i7 920 at 3.82GHz
asus p6t (just the p6t not deluxe or anything like that)
6 Gb of ram
ATI 5850 powering three dell 23 screens in eyefinity
ATI 4850 powering a fourth samsung.

the cost difference is 140 dollars between my two choices. I know you can do a core unlock on the 6950's to get access to all 1536 sp im just wondering what you guys think is the 140 dollars worth the increase in performance and the piece of mind knowing that the cards are already unlocked?
Thank you gor your advice

[DaFox]

Unlocked 6950's!

[Armenius]

It's very highly publicized that an unlocked 6950 performs as well or even better than a 6970. Plus they also run cooler with less power.

[Gilly]

Unlocked 6950's!

this

[Unknownsock]

Yup i got 2 6950's unlocked and able to run at 950 1450 is it? Well the maximum that CCC lets me.
Havn't even bothered to use afterburner for yet, it's good enough at the moment.