The .45s offer one advantage over the .50s for those that like to cast their own bullets: inexpensive mould availability. There are few good moulds available for .50 caliber at reasonable prices but quite a number of .45s that will work well.

Another advantage is the G2 Contender. But TC will be selling a .50 step-up barrel for it next year if my info is correct.

I think I need another G2.

One thing I've noticed over the past many years is how the .45 gets "rediscovered" every few years. Huge rises in popularity followed by sharp declines - only to repeat again at some point in the future. Weird.