This year I'll upgrade to a new computer and CS4. I had planned to buy the computer later in the summer and then CS4 after that, however, I've started getting work files that were created in CS4 (mostly illustrator and photoshop) and it's become a hassle to deal with so I'm beginning to think I'll just go ahead and get CS4 now. That will mean using the programs on a G5 iMac for a while until I buy the new computer later in the year. Mostly we're talking about working on photoshop files that run from 40MB to maybe 150 MB If you've gone this route, or know others who have, what's your experience? Can I get acceptable performance on an aging G5 imac? Or should I avoid doing the CS4 upgrade until after I get a new computer?