I've never been a fan of just shooting with one camera body and having to switch lenses. I don't really care how fast you can swap lenses, it still takes more time than simply lowering one arm and raising the other. That's also one of the reasons I've never been able to shoot with a flagship body like the Nikon D5. I can pretty much shoot with two prime lenses for most of the wedding day, while carrying a small bag with 2 more lenses to rotate in and out if needed. With that being said, I need a good setup for carrying and shooting dual bodies on a long wedding day.
About 2 years ago, both Sandi and I switched over to shooting the Holdfast Money Maker from the dual Spyder holster. We were both tired of having to walk sideways through tight spaces, as wearing the belt made you about 10-12" wider with a camera on each hip. It's a nice system, but there were a few things we didn't love about them. So, onto the Money Maker.