Beer is a solid option to fill up empty space in the bag. :|Funny, but putters seem to be the one category where I sort of "let the disc do the work". Mids and up and my bag is mostly neutral to slightly overstable disc and I prefer to make them do what I want.
I'm over 50 and only started playing about four years ago so I don't have any weird ambitions or dreams of playing in the open division. I do like to play to the best of my ability though.
Also, if I am being honest with myself, I could probably get away with an Envy or two and call it good but then I'd have to add something else to the bag so the discs don't flop around and whatever I add might complicate the rest of my game.
Actually I fill up the space with four or five of the same disc; I've got discs that have been in my cart for years that have been thrown maybe a dozen times. They are really just there to keep the other discs from flopping around and falling out. Which is another dirty little secret of the six Roc guys; don't tell anybody. :|