I have tied a lot of parachute flies on curved shank hooks and they work just fine. It's not to say that I don't like the Daiichi 1160 and 1167, but you have to remember that we are chasing creatures with the brain the size of a pea. Sometimes they are very picky and "educated," but a small difference in the curve of a hook really isn't that big of a deal.
I like Klinkhamer specials a lot, but in Hans' words I guess I'm tying them and fishing them wrong because i'm modifying just about everything about them. In tying there really isn't right or wrong as long as fish eat.