I like the idea of optimizing your gear for maximum performance within the limitations of practical concealed carry.
That's one reason I don't shoot IDPA.
Gear that's optimized for concealment, retention and speed (AIWB under a T-shirt) is illegal even though that's the way I carry every day.
Impractical gamer gear (the infamous "Vest") is not only allowed, it's sold in the official IDPA web store.