Save yourself the aggravation and get either an Arca B2 or Arca Cube and you'll never have to question your head choice again. Both are painfully expensive but second to none in use and performance. The Cube is geared and very convenient to use and level, and has a built-in pano-clamp up top, but not overly massive and thus marginal for systems over 15 pounds IMO. The B2 is a bi-axial adjustable ball-head, making it very simple to level any camera -- even massive ULF view cameras -- and has a load rating of 150 pounds, which may in fact be conservative...
For an MF tripod, I would look at the new Gitzo 3xxx series carbon fiber, or if you want the most rigid pod, a bigger 15-sereis is rock-solid. (PS: I am selling a near-new 1548 Giant in the FOR SALE section if interested.)
Cheers,