I've owned a 2.26GHz 8-Core for about a month now, and I'm not impressed at all. I've got 16GB RAM, Radeon HD4870 graphics, a Velociraptor as my boot drive, and 3 WD 1TB Blacks for the other three SATA bays. I'm running Final Cut Studio and Adobe CS4 Master Collection every day. I use Photoshop CS4 and After Effects CS4 the most.
I'm just not impressed with this 2.26GHz system at all. Honestly, my original Clovertown 3GHz 8-Core with 16GB RAM seemed just as fast, if not a bit peppier. First of all Photoshop CS4 on a Mac blows anyways. Its so much slower than the Photoshop CS3 I was using before. But I really expected better everyday performance from my new machine, and I'm just disappointed is all.
If I could go back, I probably would have got a Quad 2.66GHz with 8GB of RAM, upgraded to 4GB chips when the prices came down, and I probably wouldn't have known the difference from this 8-Core. I'm starting to think that a higher clock speed would have benefited me more.
I'm REALLY disappointed in my 8-Core, and Photoshop CS4 as well. I'm pretty positive that I'm going to sell the 2.26 in the next 6 months when I'm done with the project i'm working on.