What does ZEN look like? I googled around, but couldn't find anything.
I've debated buying a copy of AmigaOS 4.1 Classic and running it on FS-UAE, but at this point I'm holding out for an A1222. Which brings this thread back on topic. 
If you're curious and want to "preview" 4.1, it's very cheap to buy and try it under emulation before you decide whether it's worth buying actual hardware for. I'm running it in WinUAE, and it's surprisingly capable, especially with the UAE display driver. Not enough RAM and speed for heavy websites and apps, and no 3D acceleration of course, but you get a good "feel" for it.
Still a bit interested in the A1222, though my interest is kind of dropping off the longer it takes.
