I have only purchased a few holsters for my MP Shield. Here are the holsters I have and a quick opinion.
Wilson Combat LoProfile II Holster - this is one of my favorite holsters to date. I know it’s not inexpensive, I’m not usually the type to spend over $50 on a holster, and it’s not IWB, it is high ride and hides well under long shirts. Despite those facts this holster is fantastic. It sits high enough that if your shirt was to come up and show the gun with this holster it would with an IWB holster as well. It sits tight to the body and is very comfortable. Worth every penny. This is one of my favorite holsters for sure. Very well build. My favorite part is how the belt slide through the holes. Very cool.
Desantis Dual Carry II - if your looking for a IWB retention holster this is worth a look.
DeSantis SofTuck Holster - very similar to the Dual Carry but no retention. I don’t like the clip that comes with this holster so I replaced it with the same one that comes with the Dual Carry.
Concealed Carry LLC - This is just an inexpensive plastic holster you can buy on Amazon. I like it. You probably would also. Veteran owned. I actually pulled the clip off, put some Velcro on one side and use it for off body carry in my shoulder bag. I plan to buy another to use IWB.
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I find both DeSantis holsters very comfortable, hide the firearm well, draw very quick, and have adjustable cant.
I also have a holster for my Kahr CW9 that is just a cover for trigger guard with a clip. This style is great for hot weather since it is very low profile. I plan to get one for my Shield soon.
I tried an Alien Gear IWB pancake highbreed and it was comfortable but very large and printed. Not for my body type. But very high quality.
But I will tell you the same as others, holsters are personal preference and trial and error. My recommendation is buy from places that you can return after you try. For me I can tell pretty quick if the holster will work or not.
Good luck.