The Q Series Minimalist ($39.99 at Quarter Master) is the one that I like. The on things I noticed about these threads is nobody talks about the pants down when using the restroom. The Minimalist keeps the weapon in place, in the pant waistband. Most IWB holsters I've seen are not capable of that retention. They are also ambidextrous, you can use the clip that it comes with it is extremely strong steel. I opted to put Comp Tac clips on my for the adjustability, they come in different sizes and types. I have one for my Shield 45 ACP and another for my M&P 40 PRO.

Comp-Tac Holsters | Concealed Carry | Competition | IWB

Q-Series Stealth Minimalist Inside the Waist Band Holster