I've had a mesh cover for my pool for the past 5 years, and the only time I have opened to a green pool was 2 years ago, (When I lost my wife and had to open WAY late).I already know I'm pulling green. I've never opened crystal clear since I had my pool installed due to the mesh cover.
I swear by them! I don't have to deal with water collecting on top of them during the winter, OR that same water getting into the pool in the spring when opening it.
I plan on opening my pool within the next 3 days, and will post pictures once done.