I purchased a hollow rock about 4 years ago and it still looks great. The color hasnt faded and it's in full sun for most of the day. I just placed another order and I'm sure it will have the same quality.
I used these to cover two utility boxes in the front of a yard in Ashburn, VA. I'm a landscape designer, and I would definitely recommend these to cover unsightly objects. They aren't 100% authentic looking, but they're much better looking than a green box and may even go un-noticed by passersby.
The rock would have been the correct size to cover my buried propane tank, but it looked ridiculous in that spot. I tried to send it back. It would have cost me $169, to do so.