I've never had C-Band (And probably wont ever be able to because of renting), but I think others will tell you there are many more "popular" channels, including a few Major network stations, and a lot more feeds of channels like RTV and even MeTV..If you have the right receiver, Ku can be a good supplement to Cable/Small Dish..I've also heard of people use FTA with Hulu/Netflix, etc..
(As others have said, Most receivers do C and Ku, but some Ku channels are differently encoded..One receiver may get a specific channel while a different receiver won't get that same channel)