yeah im just debating is it worth investing in a 800mhz G4....
Depending on how much the part is.. you might just want to consider moving up to the dual-layer M9970/A PowerBook G4 1.67 which is what I currently use and just ran into a problem with the keyboard.
The keyboard cost me 50 bucks and since I am using the PowerBook G4 for most of my everyday stuff(emailing, correspondence, some light dvd work).. it is being used more than even my mac pro.
So, it is worth it.. but the question is.. Does the PowerBook do what you want it to do? One reason why I am not going to a macbook pro or macbook is because I don't need anything that fast or sophisticated.. The following macs I use mostly(from greatest to least).
PowerBook G4 1.67 DL
PowerMac G5 Quad(just obtained)
PowerBook G4 Pismo(for OS 9 use)
Gateway P-6860fx gaming laptop(for windows or just windows nostalgia)
MAC PRO 2010 6-core
The 1st two I use about 80-100 percent of the time.. while the Pismo I use for OS 9 or as an emergency laptop if my PB G4 goes down for some reason..
My Mac Pro is only used for intense dvd ripping, encoding.. other wise, my Quad is quite capable of doing these things.