I've been planning to get the g9x but just realized that it only seems to have 2 macro keys; the forward and back buttons. I used to play some mmo's such as wow and swtor but stopped a while ago. I was a clicker and when I start playing again (I may also play StarCraft), I'd prefer to start using macros keys more. I bought a mechanical keyboard without any extra programmable keys (it doesn't have the numpad, but it does have function keys). I also play some fps games too though.
Do you think two extra keys is enough? Do you prefer to use the keys on the keyboard for macros instead (like function keys)?
I never used macros much, so I don't really know how many are necessary.
In the end I'd say that the number of macro keys you need on a mouse depends on how many skills you think you may need to do at the same time but can't be bound together in one macro. Personally I'm using a SteelSeries Cata mouse playing WoW as a healer. Between the mouse and my keyboard I have 13 different macros bound to keys. 8 on the mouse and 5 on the keyboard. Thats on top of the normal hot buttons that are built into the UI. I would suggest that you get a mouse that has about twice as many macro slots as you think you'll actually use. This give you some head room for more macros later if you decide you needs some extras and will give you some flexability in what buttons you tie to the macros. Also, and one of the things I like about the Cata mouse, having a mouse that will take multiple profiles give you a lot of flex as you can set different profiles for different toons and games. Hope this helps.
I personally have tried using a lot of different mice and have learned that there is a point that too many buttons is a bad things. Having your thumb trying to managed 10 buttons, for example (razer naga and logitech G600), presents a lot of new challenges. The most buttons I can stand is what the Logitech G700 has, which has 4 thumb buttons. With more, you are constantly clicking the wrong key, and picking up and moving the mouse is a challenge without pressing a button on accident.
I recommend something like a G13 game pad. Having 4 fingers managing 10-20 keys is a lot easier than 1 thumb managing 10. You can setup a script so that the thumb buttons on your mouse change the behavior of those 10-20 keys, so it is like you have 3 times as many hotkeys when used together.