Photo settings I was playing with:

ULS Versa 40W (max speed: 60ips)

Photoshop
Adjust photo until it looks best.

Driver
Power = 14 or 15% depending on material. (The material is very sensitive to changes in this setting.)
Speed = 80%
LPI = 500 (-5), PPI = 1,000 (Versa default)
Dithering = Halftone (Built into driver)
Image Enhancement (I used default values, optimizing will help)

Laser
1.5" lens