The FAQ on the CZ website says that you have to remove the rear sight to know what height to get (model 4, 5, etc). On the Meprolight site for the CZ 75 sights, it says that the standard is the number 5 sight. For those of you that have changed these out, what has been your experience? Are they generally number 5's, or do they vary for the most part? I have noticed that the rear sight from the factory is a little over to the right of center, but it shoots dead on.