Green is more visible in daylight but still only good for a short distance. It also makes a visible line to the source when turned on at night.
My brother in law has a LC9 with a Veridian and I've held one with a Crimson Trace. I don't know which is better but I personally liked the Crimson Trace model better just for the way it activated.
I thought about one for awhile but ended up going with a set of TruGlo TFO (tritium with fiber optics) sights instead. They are a really nice upgrade from the factory ones.
