I’ve got the G700 which only has 3 buttons on the side (but is otherwise much the same) and it’s pretty good, but I think I would struggle with more buttons. I have a game pad I can use for the other hand which works well in combination with the mouse for PC games, but I usually have to write myself out customised instructions for each game so I can figure out what I’m doing.
I probably should take next week off work just to be sure.