I was lucky enough to get a belt scabbard for a mag. It holds the mag parallel w/ the belt right in front on the left of center. Those that stick up and down must be very uncomfortable, getting hung up on everything. I cant imagine using one like that.
Weather permitting I wear a fobus paddle holster, and the dual slot mag holder that came with my xd. At work or in the summer I use a black hawk own holster, with one spare mag in my rear pants pocket next to my trusty can of grizzly.
i carry spare mags/speedloaders on my left side, mags in isreali style mag paddle holster(plastic material) and speedloaders in police style belt rig....i usually wear 511 tactical canvas over shirts which are heavy yet designed to hide things on your belt line and at same time facilitate easy retrieval so i can carry 2 spd loaders or 2 spare mags and no one notices
One mag goes in the weak-side jacket pocket. If I have two mags, the second goes in the strong-side pocket so it weights down jacket, thereby helping hide the gun.
