I have had my Z60m since Jan of 2006 (delays in shipping). It has been a great experience. I love the performance (even with a single memory chip) and I love the monitor. Battery life is amazing (up to 7.5 hours with wireless off, or around 5.5 with it on).
Only had one problem -- I use the advanced docking station with a dual DVI PCI-e card in it. I use this to split to a digitaltigers setup on my desk. There is a conflict between the ATI card in the PCI-e slot and the one built into the laptop so that you can not run both the LCD and the external at the same time. In addition, the same resource issues cause problems if I put to many USB devices (3-4) into the dock.
Even with these problems, this is the fastest laptop I have been on in a while that is still portable.