What you need it for? I'm assuming you are going to be using all the Macro keys for... well... macro's.
First, decide if you are going to need 12 or 6 macro buttons. then, Decide if you actually are going to need those keys to map Macro's to.
I Met a guy at rAge who bought the Naga. I asked why he did it and he told me he needed the Macro's because he PvP's in WoW, but thats just one example.
*edit: Never owned a Razer, so I can't comment on build quality/ usability etc.