Feisol tripod question
I plan on purchasing a Feisol tripod in the near future for bird photography, and in looking as a few of their offerings I am a bit confused with the differences. I am told that for the money they are a great value. For example the CT3442 with a CB40 head is the same price as the CT3441S with CB40D head (though from different suppliers).
Can someone who is familiar with these products shed some light on the differences and I suppose advise if I am headed in the wrong direction? I should note that I will be working primarily with a Nikon D7000 and a Sigma 150-500.
thanks in advance.