Gorillapod for D7000 w/big lens?
I have the gorilla pod focus and it is surprisingly strong.
Check out this customer video review as he has a 70 300 set up on it like a tripod. (not wrapped around something)
When it is wrapped around something, it obviously has more strength when it comes to off balance and extended length of long lenses.
Personally I would use a different tripod for the sigma, but I would also trust it on the gorilla pod when used properly.
I find I use it more for my flash than anything, but there are endless creative abilities this thing holds.
One more thing to add. The ball head, or a ball head period in my experience is necessary to be able to maximize the balance. At times, you will not be able to adjust the legs when it is wrapped around something to get the camera level.
I would not consider this a primary tripod. It has however been useful to me when attached to a tree branch pointed at a bird house quite high with remote and a 70 200 attached to a D7000.