I've never successfully implemented it, but I understand the theory behind it. The elimination of the wall clipping is my Holy Grail and it looks like you may have finally licked it or are on the verge of it. You'll have to play with the weights until you get the right magic numbers. Also make sure that the clipping is eliminated when the camera is tilted up or down as well. The ultimate test would be successfully ridding the clipping with a more traditional 3rd person chase cam like a Max Payne or new template 3rd person style. Good luck.