Hello,
I have a Feisol 1431 coupled with a Markins M10 Ballhead, this setup is enough for My Bronica SQAi with the 180mm lens, or even the Nikon F100/D200+Grip+80-400 Combination.
I have the tripod since May. On the positive side, I can say that this tripod has a very good price/weight relationship, it's stable and I like the fact that you can buy it without the center column and shoot comfortably at ground level.
On the negative side, we have to be extra cautious when extending the tripod completely as the last section of the legs is quite thin and not that that stable. The leg angle is not as wide as the one of my old manfrotto 055, so when using the tripod without extending the 1'st leg section it's on uneven terrain may prove difficult. After 4 months of intense usage, the legs are starting to be more loose, so I'll have to tighten the screws to make them more stiff.
Hope this helps.
Regards,
-Rui