Yes, good hubs are worth it. White Industries, Chris King, Industry Nine, etc. Those three are all made in the US, if that kind of thing matters to you (being from AUS, maybe it is a negative since it is further away). There are several other good options.
I have both centerlock and 6-bolt. Centerlock is more convenient, and the rotors in general are better at heat dissipation (although I have never had trouble with my Icetech 6-bolt rotors).