Yes, as I understand it, inserts can get much sharper than brazed carbide. Since they don't have to worry about brazing it onto a cutter body, they can choose a composition that is finer grained and capable of attaining a keener edge. HSS can get sharper by all accounts, but it won't stay that way for too long.
Jared, looks like the overlap between some of your cutters may not be quite enough.