Sig,
Regarding looks, it depends on what you're after.
Carbon fiber gives you that black woven sheen appearance that many consider cool. If you're going to paint the surface then it doesn't matter.
If you're talking about surface finish and smoothness, that's more a function of the molding process and gelcoat (if any) used.
For example the 04 Z06 hood is a carbon fiber outer shell with a inner support of carbon/glass bonded to the shell. In this case, it's painted, but the hood is lighter than a plain fiberglass sheet molded part.
Syonara,
One trick I use is to spray the CF cloth with just a bit of clear varnish or acrylic (i.e. Krylon from an art store). It helps to hold weave together when you cut it and it doesn't seem to affect the wetting and formability too much.
-Jim