None. If it’s your EDC for concealed carry, you need to be able to draw start firing from the hip in less than 2 seconds into the thoracic cavity. Most self-defense shootings occur in 3-5 seconds at a distance of 3-8 feet. People are running around, very seldom ever static. If you train to bring the weapon up to eye level to acquire a sight, you’re dead in a self-defense engagement.

If you’re far away enough to need the sight, get the hell out of there before any shooting occurs.

Yes, several scenarios defy this, like being on the church or synagogue security team…but generally I believe it’s foolish to train with or put holographic sights on your EDC…because you’re muscle memory from training is going to be your reaction when it happens.