I've been carrying my Shield in an Alien Gear hybrid IWB for a year and a half or so. Overall, it is a pretty good holster, especially for the price.. I also have a CrossBreed SuperTuck for the G26 I used to carry. Between the two, I kinda wish I would have bought a SuperTuck for the Shield. While the Alien Gear is a good holster, for me, the SuperTuck is a GREAT holster. The SuperTuck is more comfortable and conceals a little better. Not much of a difference, but there is a difference.
On the plus side, the Alien Gear was half the price or less than the SuperTuck. The kydex is also screwed on versus riveted on, which allows easy retention adjustment and swapping parts if necessary. You can order just parts for the Alien Gear, where the SuperTuck is what it is and there isn't much you can do with it. The leather and kydex on the Alien Gear are both thicker than the SuperTuck which is good and bad. Probably more durable, but more bulk to carry and conceal. I also like the belt clips on the Alien Gear a lot better than the SuperTuck. I have some small problems with the clips on the SuperTuck riding up on my belt and poking my side. They've never come off the belt, but there is a little play because the clips are a little bigger than the belt, so they ride up to where the stop is and stick up above the belt a little. The clips on my Alien Gear just stay put and don't ride up. Minor problem, but a problem nonetheless.
In the end, like I said, I kinda wish I had bought a SuperTuck for my Shield, However, like I also said, the Alien Gear is a good holster and works out pretty well, especially if you are on a budget like I was when I bought it. They are a good option, especially for the price difference between it and the SuperTuck if you like hybrid holsters. All my complaints are really just nitpicking the differences and, overall, the Alien Gear really does work pretty well. Check them out.
Bub75