I recently added a 105 to my dual 533 G4, and I couldn't have asked for an easier install process. Once it was in, I installed iDVD 3 and everything was hunky-dory. iTunes 3 recogized it, Disk Burner recognized it, and it worked like a champ right out of the box.
I have heard of an issue of kernal panics when a drive is installed, but turning off the "put hard drive to sleep whenever possible" in the energy saver control panel fixes it. Not sure why though...
Go for it. I got mine for 280 shipped, and I've seen it for as low as 199