Thanks Jack 
please would you let me know how the gimbal worked out for you?
Hi Elsa;
Didn't have much luck as far as sightings go, but can definitely say
the handling of the Wimberly WH-200 Gimbal II head made me immediately realize I should have bought it a long time ago.
I had a sturdy ballhead previously (RRS BH-55 LR: w/ B2 AS II Clamp), but it is a toy compared to the Wimberly WH-200 Gimbal II. (Nice for cameras w/o collars, and small lenses, though ...)
With a sizeable lens, on a tripod collar, a regular ballhead is inappropriate ...
I am in the process of selling my 300mm VR II, and looking to get a 600mm E FL ED, and it will be especially important to have the right head on that piece of glass.