Hi, sorry it took so long to respond...I don't always review these like I should. I think a multiple system is always best so its not either/or but how to best provide yourself with both if you feel the laser is a good tool. Flares come in various sizes for a good reason, they are made to draw in the rescuer. A pen flare can hardly make it above taller trees and is very limited in distance visibility. A large parachute flare is better for initial notice. Once that is established you can lead a rescuer in via smaller and smaller flares that pinpoint your location (i.e. on this side of the bay...on this island...on this SIDE of the island...Right here!!!!).
The laser is visually effective for long distances at night but I don't know how totally reliable they are. They are certainly easy to carry, but expensive AND require batteries.
Don't forget the signal mirror, for daylight its highly effective. It would be a good tool to use with a laser for 24/sunny/cloudy signalling options.
Thanks for the comments. Safe paddling..