Which is better a comb or brush?

I think if your hair is fine without combing or brushing then there's no need to start just so you can say you brush your hair. I also have long straight hair that rarely tangles, but I still need to use a comb every now and then. At least once every 2-3 days to smooth things out. You're so lucky you don't need one at all!

But if you still want to get a comb, then get a wide spaced tooth one with no seams. You might want to try out different materials. Lots of people like bone, horn or wood. I've only tried wood and plastic. I like plastic better because it glides through my hair better, but yours might be different.

I don't know much about brushes because I don't have much experience with them. But when I tried a coarse boar bristle brush it broke my fine hair. So if your have fine hair too, you might want to try soft bristles instead if you ever plan on getting a BBB. Is a barrel brush the same thing as a round brush? If so, I think those are meant more for styling hair, like with a blow dryer and stuff like that.