I also ran into serious frustration when I realized the AF points do not illuminate until focus is confirmed. This is incredibly problematic when shooting in a dark environment unless you leave the focus point dead center. Even then, it's problematic, as one needs to be able to see the point in order to place it over the subject! Because of this, every time I looked through the viewfinder I was forced to move the AF point around using the directional pad simply so I could see what area of the frame I'd left it in. Doing this momentarily delayed me and occasionally caused me to miss a shot.
Subject tracking is definitely the biggest challenge for the 33-point AF system in the K-1. It failed nearly 85% of the time in our testing and made no attempt at re-acquisition (fell to back focusing and hunting in most cases) once subject focus was lost.