Yup, you'll see a boost from the CPU change. I noticed a big improvement last year when I hopped up my old Cube from a 500MHz G4 chip to the 1.25GHz Powerlogix G4 chip kit. I went from barely running one Vicky 2 at a time to being able to handle 2, or sometimes 3, depending on circumstance, the number of props, etc... Your best bet is to cram in as much RAM as possible while you're at it, though. Even w/ a dual G5 I have now, I noticed a huge boost in going from the default 256MB to 1GB, then a still respectable increase when I bumped it again up to 2GB. (IMHO, if you can afford it, save the pennies for a G5 box. The difference is incredible, to say the least, and once I saw it run, I immediately lost any and all guilt from selling the Cube and buying the dual G5 box like I had.) /P