If you're looking for a back up holster that is easy and comfortable to wear, you might want to consider the Fobus. I have worn it under sweat pants, jeans and slacks, without a problem. If you own a weapon without a hammer spur, this is the holster for you. I did a lot of checking around, and you won't find it any cheaper than at Optics Planet.
Pros: Ease of use and concealability
Cons: Velcro stitching to the holster came loose.
This review was written in the old system and had content requirements that are different than reviews written today.