What’s everybodies thoughts on disc bound planners? By these I mean the Staples Arc, Foray/Office Depot Revolution, and the Franklin Covey Circa. I’m running out of space in my desk size planner, and the interchangeable discs seem like a good solution.

For reference, I have the planner split into five sections.
Calendar: Weekly but I prefer a combined weekly/monthly. I just don’t have the room.
Reference Materials: Odds and ends from the car radio security code to twine gauges
Projects: Modified GTD index card system
Notes: Self explanatory. I will probably replace this section with a pad of 4×6 post-its.
Address book and business cards:Self explanatory