I am also interested in the full version of one of these. I am okay but not good at building stuff and it is worth a little more to me to get a device that comes complete, looks nice, and is ready to go.
Seeing that this upgrade is especially-tailored to the 600XL, I ordered one from eBay and it has been shipped now. What do I need to look at to determine compatibility? The label on the bottom, or do I need open it up? I always viewed the 600XL as the lowliest of the 8bit computers for its meager 16k memory mainly, but I even thought the 400 was better because of its nice construction and four joystick ports, even though it had less memory and membrane keyboard.
Also, I am interested in running a particular demo: The Shrine. The Shrine review. If I upgrade my 600XL with the 320XL, do you suppose I will be able to run The Shrine? I do not know if it is PAL-only... My 600XL is no doubt an NTSC one.