^ Duh... I feel stupid... Should've read your signature... Hehehe... Anyhoo... I had a 3rd market CF tripod similar to yours (Amvona/Dynatran)... Here are a few samples:
1D2N + 400 2.8L II 'non-IS' with Amvona CF tripod and ball head unit
IMAGE LINK: https://flic.kr/p/8EqpJg
1Ds2 + 500 4L IS (Mark 1) with same support as aboveIMAGE LINK: https://flic.kr/p/7AFkN6
The support was decent enough for heavy glass... If I recall correctly, the ball head unit had a maximum load weight of 50lbs, as did the CF legs... I did remember leaving the camera/lens on the support while I walked around during photoshoots and such, but after awhile, the ball head unit started to slow slip... Even with tightening on the primary and secondary security knobs, it moved just enough where I wasn't comfortable with it anymore... Eventually I upgraded both the legs and ball head unit to what I have now...
If you feel, at any moment, that your support system (legs or head unit) is losing its ability to handle your load weight, I personally would start researching for something that will give you 110% confidence that your gear is safe on it...
