I have a 4x4, with only 3 cues in it right now. I don't even need to carry the third cue, as I never use it, but I do like having it so I can make my own bridge with the moosehead I carry. (Since my third cue is mostly black, it doesn't look like a house cue, and people all over the room won't necessarily come grabbing for it, in the few rooms that I need to set up my own bridge.) I suppose it will be nice to have a spare playing cue, or at least a spare shaft, in the event that the tip on my player gets damaged in the middle of a match.
Before I got this case, I wondered what I'd need the second, bigger pocket for. Now I wish it had a bit more pocket room, like pockets all the way down the side. Something to look for whenever I decide to get a different one.