It all comes down to preference
Magholder was created over 10 years ago to solve a particular problem. The founder, Mark Houskeeper wanted a mag carrier that could be easily hidden, was durable, and stopped poking into his side or stomach since he was sitting at a desk all day. We discuss on our "Why Horizontal?"page some of the same benefits discussed in this article.
Problems with the vertical mag holder
The vertical mag holder is problematic in a sitting position for a couple of reasons. If you are sitting in a car than you can't get your spare magazine out of your mag carrier easily without shifting around to access the mag pouch. If you have a little extra baggage around your belt than a vertical mag pouch can poke you all day long even in the standing position. If you sit down at a desk or in a car than you will feel this even more.
Horizontal vs vertical spare mag reload
When Magholder was first designed, we discovered that the reload time of the horizontal mag pouch was quicker because of the more natural and smooth magazine retrieval. With the horizontal orientation it is a quick sweep of your arm back and then inserting your magazine into the pistol to reload. Check out the below video demonstrating the difference:
Practice, practice, practice
More important than picking your horizontal or vertical magazine carrier is practicing your reload over and over again.Practice in different situations so you are prepared to reload with whatever type of mag carrier you pick. We'd also recommend looking into going through some training to help teach you the proper methods to reload your magazine to give you the best method to be successful.