Before investing in them, be sure you'll actually use them. Don't buy any dimpled aliens , but other than that I think they both have their merits. I don't have any C3s, but if I was buying some gear in that size I would probably give them a go. As it is, I have it covered pretty well in aliens. I don't see reason to go C3s, especially since it would cost me a pretty penny. I think the aliens go smaller than the C3s.