I’ve never tried a green laser, so I can’t give any input on that. I absolutely prefer a WML, and have them on my G43, G19 RMR, and G19 (chopped grip) that I carry regularly. Bad things have a tendency to occur in low light.
The G19s do not have lasers. I feel that visible lasers are more valuable on small pistols. Like I said earlier, I have a TLR with laser on my G26, but I don’t really like it on that gun. It doesn’t get carried, and the only reason I keep it around is for a grip chop template.
I do sometimes carry a G42 with no light, when I have no choice but to carry a tiny gun. Its a good practice to also carry a handheld light, with or without a WML.
Sorry if this post seems disorganized.