I carried IWB behind the hip for most of my life. A couple of years back, I tried AIWB, and have been using it ever since. Wish I'd switched to it a lot sooner. It conceals a lot better, is much quicker to access, and is a lot easier to reholster with, as you can actually see what youre doing.
I dont see what the type of gun has to do with it either. I carry a Glock 17 in mine, and feel perfectly comfortable doing so.
I also use a Smart Carry with a Glock 26. Its not really a AIWB holster, but its similar. It rides below the belt, and works very well. Its one of the most versatile holsters I own, and consider them a "must have". While I have used mine with a Glock 19, the smaller guns are definitely more comfortable. Either way, its still the most concealable holster that Ive used, thats actually comfortable and quick to access.
My experience with the Pager Pals wasnt as good as woerm's. I got one when they first came out (we were actually still using pagers then), and proceeded to break it the first time I tried to draw from it.