Ive just received my LensCoat for my 50-500mm Sigma.
All I can say is what a great product it is.
All the joins in the material are very neatly stitched and the windows are in the exact correct position.
It was a breeze to fit and gives the lens a real nice feel to it.
Although his product isn't cheap, this is reflected in the care that has obviously been taken in its manufacture, and when you consider the protection it offers I think its a small price to pay in comparison with a £1000 lens.
Also a quick word about the guys at LensCoat,I had a few questions about delivery,postage and pricing etc as I live in the U.K, and they were very prompt and helpful with their advice.
I would highly recommend buying from these guys.