I have an Advantage Arms .22LR conversion kit for my Glock 17. It is nice to shoot .22LR on a platform that I use for defense. The AA kit can be a bit cranky when it isn't well lubed, or isn't fed specific ammo. However if it has the right ammo and is lubed, it works great. There is a weight difference between the AA slide and the Glock slide, as the AA slide is made of aluminum which makes it feel a bit different in the hand. Accuracy is pretty good. About the same as with the original Glock slide. Switching to the AA slide is easy. If you can remove your slide and put it back on, then you won't have a problem. Cleaning the AA slide is just as easy as a Glock slide.
I don't have any experience with the Ciener kits, however I have heard bad things about the kit itself and customer service. Glocktalk.com is where I heard most of this info.
All in all, I would recommend it...
K