I carry appendix for a number of reasons. I tried several other locations and just wasn't happy with them. I find the weapon digs in a little when I bend down to pick something up, nothing really uncomfortable, just lets me know it is there.
I like to have the weapon in front of me. Makes it much easier to guard the weapon in the event someone tries to make a gun grab. Also one of the easiest draw positions IMO. 3:00 would be fine, except for the difficulty of concealment. Takes a pretty bulky cover garment for that, and I live in a warm climate.
As to the safety issue, if you have the safety on when it goes in the holster, and train to thumb the safety off after it clears the holster on draw, the chances of an ND are negligible. If it doesn't have a manual safety, or isn't DA, it isn't suitable to carry IMO. Your opinion may differ, but that is how I feel about it.