I've owned a few tuckables. I love the concept, execution depends on how concealed you think it will be.
Below are the High Noon Alter Ego (my favorite), Galco USA, and Galco UDC.
The High Noon is available in several configurations, and is a top flight holster, with the high slide protector, top notch construction, and excellent tuckability, with bottom attachment. The one negative (and positive) is the huge ass belt loop clip. Yes it locks in place, perfectly, but it screams CONCEALED! Still a great holster.
Next the Galco USA. No reinforced opening (slimmer but harder to reholster),with "new generation" J-hook, slim and hard to see, but marginally tuckable with middle of body attachment, and really unstable, no lateral stability at all.
Next, the original "Deep Cover" Galco. The new "Ultimate Deep Cover" has the horrible USA J-hook, the original has a bottom of holster (like High Noon) attached, wide J-hook. My favorite of all, but designed for a 1.5" belt, and I wear 1.75" gun belts. No longer made anyway, but occasionally available on eBay.
By the way...the High Noon and the UDC pictured are both for the Kahr PM9.
The USA in the middle is for a J-frame.
The Comp-Tac MTAC (Minotaur):
I've tried HARD!! I've owned three. Kept trying again. I've owned every clip combination and "reshaped" all of them, trying to find a workable fit. It's just too much crap stuck down in my pants. And anyone who has a clue has to be able to see all that stuff.
The best holster of these is far and away the High Noon. But that big belt clip is so obvious. So now I pocket carry. Always.
BUT! I have a couple of .45 "compacts" I'd like to carry. I'm thinking High Noon, with cell phone camouflage. They really are top grade holsters.