After making a general choice of gear, testing it is the next step. If we buy a new vehicle, this is easy, because we drive it everywhere. We find out the things we like and don't like about the radio, the seats, and the field of view we get in our new ride. But we also are a decision on how much we like it and whether or not we are likely to replace it with something else.
Testing a gun or piece of gear is no different. We have to use the gear as it was intended. If that means a handgun, make sure it is usable in our drills and our method of employment (draw, reloads, etc). It also means using that price of equipment for what you want it to do. I see a great need of people buying body armor or a battle belt and putting it in a "break glass in case of emergency" type of role. How do we know if our arrangement of magazines, or the weight or strap tension affects us? How will we know how far we can run or walk in the gear of we don't do it. The US Army makes you train in your gear whether you want to or not. You will do marches, battle drills and even play football in your full gear. Why? To make sure that all of the personnel/gear integration is worked out.
So when you acquire a new piece of gear, make sure it actually performs the task you bought it for. It will make you more proficient and ensure that your equipment meets the task, should it ever occur.