Although My Arca Swiss would surely hold my recently acquired 810 camera, I've to decided to get a 3-way for my LF. I've narrowed it down to the either the Bogen 3057, 3039, or Gitzo 1572. These were designations I got from my old B&H sourcebook and I hope they're current. <p> The Bogen 3057 and the Gitzo 1572 are rated according to the sourcebook up to 22 pounds. Is this absolute, or is there an extra load calculated in for safety? The reason I'm asking is that my 810 w/lens/back will be close to 20 pounds. <p> Checking around, the price for the Gitzo is quite a bit more than the Bogens, are we talking a big difference in workmanship and machining between the bogens and the Gitzo? <p> Is the quick change system on the Bogen 3039 safe to use with a heavy 810?