The way I feel is that you're either using one software or another. With multibox you're able to use usb and the G15 you already have. This gives you macros and everything else. Or you can go get the verta gear, then get a software program that does the macros for you. I personally think the G15 is much easier to use with macros then any software will be for the pure fact you have dedicated keys to assign the macros. You don't assign them to a key that then becomes unavailable with a regular keyboard. Each scenario above uses software.. whether it's multibox or x-keys. With that said if you have a G15 and want to use it go with multibox, if you don't have a G15 and feel like shelling out the dough for verta go that route.

I personally use a G15 and Multibox. I wouldn't want to lose the functionality of the G15 if there was a way to keep it. I also prefer Multibox over hardware for the fact of modification. Multibox's source is posted so anyone who can code that is willing can open it up and do what they want and make it behave how they want. That opens a lot of opportunities that the hardware will never. Anyways that's my 2 cents on it.