I have mainly used mine under a 300 f2.8L and a Kirk BH1 ball head.
I found noticable improvement in sharpness of my pictures, especially when using teleconverters, over my Bogen 3221 (and it weighs nearly two pounds less !).
I am only 5'6", and while i thought this pod was huge when i got it, i sometimes still wish the legset were a bit taller (to eliminate raising the column).
I find the column to be quite good, but rarely extend it over half was as with 13 lbs of camera / lens / ballhead on top, the whole rig tips much more easily.
Overall i am extremely satisfied with it, and would buy one again tomarrow if something happened to it.