They are great on miter saws... not silly/gimmicky at all. That's why one of the top end miters (Festool Kapex) has them on board. For knowing exactly where the edge of the cut will be (taking blade width into account), they can't be beat at the present time. And for those recommending tape and boards and whatnot, those don't do a thing for you when the board you're cutting covers it.
Other tools it does seem gimmicky though.
The light on the DW718 & 780 is a better design in many situations than the laser. That said, both are good on a miter, when it's needed.
Laser beam stops being visible as the blade descends vs the light casting the blade's shadow is down to the point where the cut starts. Laser shows up better/clearer on moulding than the blade shadow. Both are hard to see at high noon outdoors but the laser squeaks by as better outdoors IME. Laser is probably a little better at odd angles since the blade width's shadow can be distorted. obvously the laser is better than the light for darker woods also. With very busy grains, both are kind of a wash, just have to be very careful with those.
I own a Bosch made Cman jigsaw that almost never gets used, and an 18v Bosch one. I go out of my way to not use a jigsaw as often, but sometimes it's the only thing for the job.
