I bought a Nehalem 8-core MacPro this weekend to replace my well-loved but aged first gen MacPro. My initial reaction was one of moderate disappointment. It was faster, but only marginally. The reports that single threaded tasks were slower because of their inability to take advantage of the multicore processors are not an exaggeration at all. I upgraded the ram from 6 to 16 gigs, which helped tremendously with the pro CS4 apps I use. I did my usual trick of making several ram disks and putting them in a raid to give Photoshop a speedy primary scratch disk. Using the extended 3d tools was finally a much better experience than the 1st gen macpro. But, looking at my CPU usage, Photoshop still would only use 10 percent of my 8-core at a time. I decided that I couldn't wait until September to get full use out of my machine and decided to take Snow Leopard and central station for a ride. First of all, it's fast - very fast. I'm getting 100 percent usage of my CPU with processor intensive apps now. 3d compositing work with Cs4, the most processor intensive part of my workflow, is much quicker and highly usable. An object I've been working with, a 600,000 polygon battle cruiser, took 10-12 seconds a change with the stock-configured Nehalem MacPro. Now, it's taking 3-4 seconds a change. If you have any questions, or have anything you want me to throw at it, let me know!