I've got a Lyman .50 that I haven't shot yet. Belt loop looks entirely functional and is how I plan to carry it while hunting.
Mine will be carried to deliver a quick finishing shot when deer hunting...as well as to have some fun at the range.
If you're a handgunner, I'd say you'll have to get used to whichever you buy. I'm a revolver guy and the Lyman is quite...different, but not bad. Seems like the more you handle it, the more natural it points and feels. Sights are more than adequate and trigger is middle-of-the-road (something you can easily get used to with dry-fire practice).
The Lyman reportedly has stock breakage issues too. They mainly occur when the gun has been overloaded or dropped on a hard surface. Since the .54 is the most powerful, it probably suffers more breakage from overloading.
On Edit: Rough handling during loading is occasionally a source of stock breakage, as well. This would be mainly from trying to get a tight fitting ball-patch combo down a fouled bore. Since the charges are light (compared to a rifle) and the ranges are short, the need for a tight fit is questionable. I plan to use an easy loading PRB combo with .010 patches at the outset.