What I like about the C-4 is the shape. When I tried hooks where the shank curves round more, supposedly a good shape for use with hair rigs, I found that too many fish barbel were dropping off. My thinking is that the point was only getting a shallow hold because of the angle of the point relative to the shank, and tearing out. I prefer the wider gape, and the slightly in turned point does seem to resist damage from hard river beds.
Apart from the overall shape, I like the fact that they are a strong hook. I am of the opinion that you should fish as heavy as you can get away with, so I prefer to use hooks that are thick in the wire which I can't open out when playing fish. However, using 30lb braid I can still open out a size 2 C-4 when it finds its way into a snag.