I've been using the advantage arms 22lr for a Glock 17 for a while, and sold a bunch to others. It has a wear in period of a few hundred rounds where you'll get jams, a few with certain ammo (blazers/minimag worked well) a lot with crap ammo (Remingtons). Now I rarely get jams except for ammo related issues. It is accurate, though mine tends to shoot a bit high.
The slides work with regular glock holsters. However since the slide is lightweight and recoil spring is light, the slide can go out of battery from a holster. Any friction on the slide, like a thumb resting on it, could prevent it from cycling correctly due to the light spring weights.
I would not recommend using one for self defense due to possible reliability issues with the gun, and 22lr ammo tends to be more unreliable overall. 22lr is also too weak for a self-defense round. I can see some people getting a tiny 22lr for max concealability knowing the tradeoff in stopping power. But getting a regular sized gun in 22lr doesn't make sense. Women can shoot a 9mm just fine, it's a training issue and not a gun issue.