Ok, I had a Mac Pro octo early 2008. I found that this was a friggin beast for my uses(Primarily Logic, Live, and day to day junk). My friend was buggin me so I sold it to him for market price - tax and I just got a quad with some perks, such as wireless mouse, wireless keyboard, and an airport card installed for only 2064 after taxes with an ADC discount. So I saved some loot. The quad is a great machine. Feels identical to my octo. The only area I can feel that it is slower is when burning a movie. I'm sure people who work with video can give a lot more examples but this is my only grip and it's not much of a big one. It used to take me a total of 14-16 minutes to encode and burn a 700mb avi file to DVD on the octo. on the quad it takes just a little under 30min. Coming from a dual core g5 this is a great improvement either way and I can't complain at all. Everything else is pretty awesome and can't really tell the difference between the octo and the quad. I can still multitask like crazy and its a great machine. I actually noticed that a lot of random bugs that I was having was eliminated, but that can definitely be a different issue. If anyone is in debate over a quad or an octo, both are great machines. If money is no object, then go for the octo. If money is an issue than go for the quad with a ADC. Can't beat the price and is a rockin machine. Hope that helps anyone that is still lingering. The Macworld review was dead on.