Some 1280x1024 monitors (the standard pixel density for non-widescreen 17" monitors) will scale 640x480 in such a way that it leaves narrow borders at the top and bottom, thus making the pixel matching "perfect". Of course, it's not exactly the sort of thing that gets advertised.
Beware that some (many?) LCD monitors won't like the 67hz sync-on-green signal that comes out of a IIci.