My brother in law has the Z, and ignoring the Mac/Windows argument it's a very powerful and very fast machine, especially if you get the dual SSD in raid config. The trackpad is a frikkin nightmare though. After using the apple one there's no way I could go back.
I thoroughly second your comment on the trackpad! I have a Dell Studio - while it does have a multi-touch trackpad, its has a mind of its own and I am never sure how much the page will scroll. To me it is many small things like this that make the Macs a much better deal than MS/Intel laptops. If people want to save money I would say buy a low end laptop from one of the other manufacturers - but if you are willing to pay the slightly higher price, Apple products are the way to go. I do not regret buying any of the Apple products I have = (many iPods, iPhones for everyone in the family, aTV, MacBook Pro etc)