I have both a Crimson Trace, on my Ruger LC9, and a LaserMax on my Shield 40. The specs of both lasers are identical. The big difference is the activation (on/off) button. The CT has the button on the front of the grip, just below the trigger guard. The LM had the button under the slide, just in front of the trigger guard. CT has been around much longer, and charges much more for their lasers.
I prefer the LaserMax due to the activation button location. It is where your finger should rest, when not on the trigger. A simple push and it's on. If you don't want it on, you don't push the button.
Crimson Trace says their button is naturally turned on, when you grip the gun the laser goes on. (1.) If you don't want it to go on, you have to change your grip. (2.) The button sticks out about 1/4 inch. Your gun grip is straight, but the button sticks out 1/4 inch so that one finger is offset from the others. This was not comfortable to me. (3.) The laser doesn't always go on when I gripped the gun. If I didn't grip it just perfect, the laser light would not go on. CT sent me a new laser replacement, saying something was wrong with the switch. The replacement did the same thing. The only way I can guarantee the laser goes on every time was with a super tight, "death grip".
I got my CT at a gun show for $160, a year ago. That was a super low price, at the time. I got my LM from EBay for $85, including shipping. Brand new unit with a full warranty.
Bob