Personally, I would go Mediator. But it's not my choice (or rather, I already made that choice and bought one ages ago (allthough not an SX... :-( ))
The list of supported cards for the G-Rex isn't very long, is it?
Whichever way you go, there's not much that beats Workbench in 1600x1200, 24bit on a 21" screen. Too bad my V3 is a LITTLE bit slow for that, so get a slight flicker due to low refresh rate. But the screen doesn't handle a lot more either, so I guess an upgrade would be EXPENSIVE :-)
