Haha, that screenshot looks so tiny on my 23" LCD.I got a 12" RGB with my free LC. I'm now using it with a Performa 6200, and the picture is very crisp. Works in thousands of colors, too. As far as reliability is concerned, I haven't owned mine long enough to know about that. If it still powers on after being built circa 1990, it must be OK.
I'd say go for it.
They are awesome Screens, small, but awesome. Very sharp. I even tried it in leopard for the heck of it.
(which is set to 1920x1080) Did you actually hook your Mac up to a 12" RGB, or did you simply set the res to 512x384? 
Just curious...I didn't think that modern video cards took to running those older fixed sync displays very easily.