Yes, the C-Wing was created as a demo. The C-Wing Ugly, a DIFFERENT SHIP, has appeared in Cracken's Threat Dossier, Scum and Villainy, Ambush at Corellia, and Showdown at Centerpoint.
Really? Those look identical to you? You don't see the massive YT-1300 cockpit in the top screen? Do you need glasses?
The only thing "better" for the C-Wing is that it's faster and slightly longer. The B-Wing has heavier armor, shields, ionic capcity, and more weapons.
And if you're so opposed to non-canon ships, btw, I'll take any YT-510s you, or whatever faction you're affiliated with, have. Same with Tabders. :D