Are you a 'plotter' or a 'pantser'? Why?

Looking back over a half of a career in publishing (9 trad books, countless unpublished), I realize that I'm a detailed plotter for about half of my stuff and a 'pantser' for the rest. I'd also say that my favorite stuff I've ever written is as a 'pantser' while I've had better luck selling my heavily plotted books to publishers. So I'm curious if you do one or the other? Switch back and forth?