I have spent years vacillating about the type of planner I use.
When I started college, I used a spiral bound planner, the most basic of planners. At the time it worked pretty well. I was lousy at keeping track of it, and if I'd used it more I'd have been way better off.
When I graduated, I got a DayRunner, and that actually worked pretty well. It was bulky, and I found I tended to leave it behind. This led to years of swapping through different sizes of planner.
Over about a five year period a few years back, I tried the Moleskine planners, pretty much every variety they make. They worked all right, but the inability to add things and move things around, made them very frustrating.
I was contemplating a return to the DayRunner when I discovered the Happy Planner, and loved the concept. I got one and tried it. In the end, I found they just couldn't stand up to daily usage for me. The covers quickly started falling off. So I picked up a half-size three-ring planner, and started that. I hole punched the Happy Planner pages and put them in the binder because I liked the format of the pages.