It depends which one your taking about the 3371/3471 I would not recommend the 3372/3472 I would. I had the 3471 and the locks broke on it, they are casted where the 3371/3472 are CNC'd and are much stronger. That is really the main difference between them the legs are the same I think. I broke mine when I had the legs set down low with a 500L, a few times it slipped and then finally it broke. You can see how it broke here.
I switched then to the 3472 and no problems since, I know another guy who has the same one and he uses a Nikon 600 and no issues.
a word of warning do not buy from feisol.net I have read some bad things about them, buy from Kerry at reallybigcameras.com he is really good
as for their gimbal I have never seen one so I cant comment on that