I can't think of a rifle/carbine class where you would need a chest rig. A lot of people wear and get good use from them. In some cases the class lineup is comical when you look at all of the gear. But needed? I don't think so.
Your actual reloads should be from your belt. The best way to use a chest rig and similar gear is to replenish the pouch or two you have on your belt that you use for actually reloading the rifle. There are a variety of ways to carry multiple mags in a class to feed your belt pouches, including something as simple as a dump pouch, also mounted on your belt.
I've heard that from several people. Thanks for the inside. I guess I shouldn't have passed on the HTC sale.