MY SA mags "stick" when unloading them and haven't proved very reliable as yet. I much prefer the performance of my Ram-line 15 shot magazines.
You'll find yourself shooting in the ESP class, and yes that magazine safety is a pain when unloading and showing clear and dropping the hammer.. until you get it pinned you'll have to carry an a empty mag so that you can drop the hammer.
Even the standard 13 shot magazines work for IDPA and they are still cheap. The "practical" model carries better sights and the 2 tone finish and pachmeyer grips, its magazines also had bumper pads.
Cool thing about the hi power.. depending on the holster, many of them will also fit Colt's Gov. Models and clones.