For those saying the Dark Grey is a good all round lense, I guess it depends where you live. Im from whistler and we barley ever get the right weather to use the dark grey. Unless its bluebird the Dark grey is fairly useless. It adds no contrast to the terrain unless its clear.
The Black iridium is a better all round lense. I use that most of the time, the HI yellow for cloudy days and save the dark grey for the blinding bright days and summer use on the glacier.