This question is actually a continuation of previous questions asked by me and o thers. Previous questions have established that placing a pan head between your tripod head and camera is an effective way of not only leveling your camera, bu t doing it in a way where it stays level even if you pan. The alternatives prev iously described are to either level your tripod, or place a leveling base betwe en your tripod and head.
I was recently talking with the folks at Really Right Stuff about this approach, and they *strongly* discouraged it unless the tripod head manufacturer had fact ored it into their design. They argue that placing a pan base above the tripod head raises the height above the head where the load is supported, and is thus m ore unstable. Common sense would say their argument is correct, but in reality is the extra stack height enough to make any reasonalbe difference? In my case, the players involved are an Arca Swiss B2 head and a 6.5 to 9.5 lb camera and l ens. In most cases, the load can be centered. The pan adapter I was considerin g is made by Foba. The additional stack height of using this part including the needed plates and adapters on the top and bottom of it would be about 1.9 inche s. RRS advocates using the Gitzo leveling base instead (I don't always use a ce nter column, but the Gitzo leveling base precludes the use of a column entirely) .
I am aware that Arca Swiss is consider making such a part as I describe for thei r tripod heads. I am discounting using their potential product for two reasons: (1) availability (it will be released *sometime* next year) and (2) it is not c ertain it will work with older B2s (more than about a year old).