[iBook] USB cam or iSight for 600MHz G3 iBook?

[David Crump]

I'm getting set up to do some iChat AV with my family and came across this:

http://www.macally.com/spec/usb/input_device/icecam.html

Has anyone had any experience with this?
I realize that the iSight would be much better, but as far as a 600MHz G3 iBook goes, I was wondering if this would maybe be a better option.  I thought that because the 600MHz G3 was the bare minimum to use iChatAV, that maybe a lower resolution camera would actually help out as far as performance goes??  Correct me if I'm way off on this.  I realize that it requires a software add on to make it work with iChatAV, but I didn't think that would hurt performance.  Anyone have any input on this one?
Dave