Graphics Upgrade Advice

Hey all.

I'm thinking about upgrading my graphics card. I'm thinking about getting a 6950 which I'd flash into a 6970, but I'm not sure if it'd actually help my performance at all, due to the rest of my system. So my system specs are

Intel Xeon Cpu 3.20 Ghz, Quad core
4 Gigs DIMM ram
2 300gb Raptor drives in RAID 0

My current card is a 512 Mb radeon 4850.

So what I'm asking is would it be worth it to upgrade to this card? I'd probably do it even if the increase in preformance wouldn't be huge, as I'm planning on getting an entirely new system in the future that would use the 6950 anways.

Thanks alot!