Comments about LensCoat LensCoat Lens Cover for the Sigma 500mm f/4.5 Lens - Realtree ADvantage Max4 (m4):

The neoprene they use for this is rather thin, so it will provide protection from cosmetic marks caused by minor bumps and everyday use, but doesn't add bulk to your lens.

What you can't tell in the pictures is that some of the smaller pieces are adhesive backed and are prone to come off. This is the case with the lens collar, rotating carry strap collar, and the drop in filter ring. Also, the focus ring is not covered, which for the price you think they would give you. This is supposed to camo the lens and the focus ring is quite large.

With all that said, I still would probably get it when you think about the cost of your lens compared to the lenscoat.