Maybe you've noticed - we're minimalists. We have very simple philosophies when it comes to holsters and concealed carry.
A holster has a single, primary job. To hold a firearm. If it doesn't do it properly, there is no reason to even think of using it. Sadly, in today's marketplace, the fact that a holster simply holds a pistol well makes it a good holster.
Beyond hiding your weapon, a concealed carry holster has to have three equally important attributes to be really great. These three things are a lot like a three-legged stool - take one away, and the thing will work, but not very well. Take two away and it'll work, but you have a lot to compensate for.
Does it cover the trigger guard? This should be a no brainer.
Does it allow a proper grip on the gun? The grip you establish on the weapon in the holster is what you are going to end up with. You don't want to try to change your grip once you get the gun out of the holster. You run a huge risk of fumbling the gun and it's valuable time you should be using to acquire your target.
Does it offer a clean presentation so the muzzle doesn't cross the body? Rule number two of gun safety says, "Never point your weapon at something you aren't willing to destroy." Again, this should be a no-brainer. (Pay close attention "Texas-carry," palm-out, behind the back carriers!)
Does it keep the gun secure in the holster during normal activities? A weapon that doesn't stay where it's supposed to is useless.
Can you quickly get to the gun? Time is of the essence.
Can you effectively get to the gun? Even if you can get to your gun quickly, you need to be able to get it out easily.
Can you draw and reholster with one hand? Can we suffice it to say that this just makes sense and not take up the time to go over it?
Can you make normal movements with comfort while wearing the holster?
Can you sit comfortably for periods of time if necessary? If you sit in a car or at a desk a lot, you'll want to make sure that the holster you select is comfortable enough to last throughout the day.
Keep in mind - some say, "a concealed weapon should be comforting, not comfortable." This makes a cute saying, but ignores the fact that most people won't wear a rig that isn't comfortable.