There will be no comparison between the 5850 and 580GTX as the processors are different generations and I really can't see Ram making much difference.

I am very interested to see how you go with the IBIS. I have been tossing up whether to upgrade my 2 x intel X-25s to an OCZ RevoDrive 2. As far as I understand, the IBIS just uses a proprietary bus which connects to the PCI-Express port rather than a direct connection like the Revo/Z-Drives, so performance should be pretty similar to 4 drives in a raid 0 setup regardless.

Also looking around recently, it seems that the new SandyBridge stuff is available at very good prices and will perform comparably to an X58 980X setup. It also seems that they are extremely easy to overclock (the K versions only) but they are limited to 4 cores. From what I have seen though, clock for clock, a 2600K chip will achieve similar results to the 980X even with the extra cores. If I was upgrading from Core2 I would probably look at this platform currently, if I was upgrading from i7 then I would probably wait for the Sandy Bridge E stuff to come out later this year.

I know you have already bought the gear and it looks like an awesome package mate. Either way, you will have heaps of fun with it which is the main thing