Arca-Swiss is probably the best brand in the world for ball heads and brackets or other pano devices. You cannot imagine the precision of these things before having them in your hands. I use P0 and P1 heads on Gitzo tripods. P0 is smaller than P1 and fits perfectly my Traveller Gitzo Tripod. In order to get full comfort when attaching Leica M on the tripod I use Mini L-Bracket: it is gorgeous, rock solid, tight attachement, quick shift from horizontal to vertical, with a precise and secure attachement to ball head. No other brand propose such quality in a L-Bracket !