I'm an Alien Gear fan. I have a Cloak Tuck 3.0 that hides and carries a full-sized M&P M2.0 very comfortably. I sometimes have to check that it's still there it's so comfortable. It's also very secure for an open-top IWB holster. The material facing the gun is a vulcanized rubber that grips the gun, but not so much that it impedes draw. Tension is adjusted by the Allen screws securing the Kydex shell to the backing. Alien Gear has upgraded the Cloak Tuck to the 3.5 since I've gotten mine.
A word of unsolicited advice here..... If you spend the money on a good quality holster, you should exercise due diligence on purchasing a suitable purpose-designed belt too. I like nylon belts. I have belts from 5.11 Tactical and The Wilderness. I like The Wilderness Instructor belts the best. They have a polymer reinforcement sandwiched between two nylon layers. They are then stitched along their length with either 3 or 5 rows of stitching to to stiffen them up. They make a BIG difference in how the gun carries on you.
The 5.11 belts are okay. The nylon is woven a little thicker and coarser and they are also stitched along their length, but they don't have the polymer reinforcement. I bought the 5.11s because I have several pairs of their pants and the belts are color matched with the pants. Plus they were cheap at Dvor. I have three in coyote, OD and black.
If you need or like leather, there are several makers that specialize in belts for concealed carry.
[sql][/sql]I have several holsters for my 9mm Shield, IWB, OWB, leather and Kydex; the one I use the most is my Vedder Light Tuck with claw attachment. It's very comfortable and the claw attachment helps prevent printing. The big advantage of Kydex over leather is that it holds it's shape and resists being compressed by the belt tension, making re-holstering easier and safer. I agree regarding getting a nice gun belt. I like the look of a leather belt and really like the Bigfoot Gun Belts with a steel core that is nice and rigid yet comfortable. It's held up very well.
ps. I have a Sneaky Pete for my Ruger LCPII and it's perfect for that and never gets a second look from anyone. I never bought one for my Shield as I think they look too big to be mistaken for a cell phone case.