The two plastic paddle holsters I have position the pistol too far from my body to easily conceal. Therefore, I only use them at the range, where I can openly carry. They are however easy to get off an on, and it's easier to holster the weapon as compared to a tight-fitting leather holster.
My leather belt holsters hold my pistols much closer to the body, so I can conceal with a normal shirt. I will sometimes thread the belt in front of the hoster instead of behind, as this will pull the pistol in even closer.