So later that day I went out to shoot a bit and zero the laser. Before I actually shot it, I dropped in my Sightmark 9mm laser boresighter and put laser-on-laser at about 20 feet. The adjustment screws are treated with blue loctite, so they take a little torque to turn but the included allen wrench worked perfectly. Note that the pistols frame warps a little bit when you apply torque, so I had to adjust a bit, then let off to see what the actually point-of-aim was.
When I got out the the "range" (innadesert), I shot off a few rounds at about 20 feet. It was damn near right on, just a few inches right. I adjusted it leftward and down a bit, then shot at about 15 yards. Right on again, so I adjusted just a little more and shot at 20. Perfectly on, great group, and lined up perfectly with the irons. I shot another magazine with irons, then one with the laser, and found all satisfactory.
Overall I'm extremely pleased with this light, and it's pretty much exactly what I was looking for. It does have to come off the gun for battery replacement, and I'm not sure how that will affect the zero, but I'll find out before too long because I can't stop playing with the damn thing. I've picked up two sets of spare batteries just to have around.
Final notes. I forgot to mention that with the light and laser both on, the laser dot is still very easily visible in the beam. My camera had trouble capturing it though. The build quality, functionality, and fit are superb. I haven't put the gun through too much abuse with the light on it yet but knowing me, it's sure to be well tested. I have high expectations. My only complaint with the light is the primary on/off switch. It's the only thing on the light that feels "flimsy", though I have no reason to suspect it actually is. It's not particularly smooth, either, unlike the mode selection switch which is solid and decisive. Since I spent my break in Arizona, I dicked around with holsterless conceal carry and found that the switch absolutely loves to catch in your waistband, usually requiring two hands to remove. I don't generally CC the pistol, but it's something to consider.
Next up, Factory Glock extended slide release.