That`s a GREAT CPU for HWBot submissions (benching) on DICE/LN2 cooling as it has unlocked multiplier..
Downside is that it has 80C Tjmax vs 100C of Q9550 so it needs a TOP LINE cooling..
In everyday usage and OCing up to 4GHz on AIR it has no real advantage on Q9550 as Q9550 E0 stepping on right board hits 4GHz relatively easily and uses less Vcore (runs cooler)..
I say sell it as it`s priced nicely..
If I got given that chip, I would obviously use it in my sig rig, but unless you have use for another rig I wouldn't say there's any point in building something up with it.
You could get a ton of cash for it, though. The higher end C2Qs are worth a lot more than Phenom IIs.