If you're considering an imac make sure that you can live with the glossy screen. ( I believe that Michael uses an older model iMac with a matt screen ). I've also heard that there are issues regarding the calibration of these screens. I've got a Mac pro and a 20" cinema display but I sometimes work on someone else's 24" iMac: It's powerful enough but I hate that screen. It also had to be returned for repair when it was about 6 months old as did another friends previous generation iMac.
My Mac Pro is over two years old and has had no problems. My previous computer is a 9 year old Powermac G4 which is still going strong ( no problems ever ) as is the Apple CRT display that I bought with it ( ! ). However I can't help feeling that the consumer level Macs just aren't as solid and that Apple seem more interested in phones and ipods at the moment.
Have you considered building a PC to your own spec for imaging use and keeping your older mac for internet / fun stuff?
Thanks for your reply. I've heard the same thing regarding calibration issues with the iMac screens. Also, like you, I'm really not sold on those glossy screens. A guy that I work with just bought a MBP a few months ago, and that glossy screen is not easy to look at; everything in the room is reflected back! I hadn't heard of any particular repair issues, but I'll certainly keep that in mind.
Right now I've got a 23" Cinema display on my G5 tower which I've been very happy with for several years, and the only repair I've ever had to do was the cooling fan in the tower. Shortly after I bought the system it started making this churping sound; Apple fixed it quickly and I've never had another problem. Overall, I'm perfectly happy with my current setup. I have considered building my own PC since I have a VERY knowledgeable friend who has already offered to help.
Thanks, again, for your comments.