The Sun Rays are basically dumb, network attached frame buffers. There is VERY little logic on these things, the network requirements are very high for them, since all audio/video has to be blasted across the network (as opposed to X terminals, which send X events).

They run pretty well, though, the more sun rays you hook up to a server, the beefier your network and servers need to be.

Sun had serious issues with the Sun Ray's at JavaOne last year.

(Man, I wish they still called them corona...)