Moonclip revolvers are better for self defense than wheelguns that load traditionally. Moonclips aren’t subject to the biggest issue you run into with speedloader guns – sticky loading or unloading. In a speedloader gun, individual rounds will sometimes stick in the chamber, making the reload a lot more difficult. With a moonclip gun, all 5 or 6 rounds come out at once. Similarly, when you’re loading the gun, all the rounds go in at the sake time and there aren’t any issues with discarding the speedloader when you’re done.
However, moonclip guns aren’t without their disadvantages. One of the biggest issues a moon gun can run into is extraction. Generally, having all the cartridges connected by a clip means they all extract better, as noted above. However, I have seen a moonclip gun with a case that splits in the chamber, which ties the entire gun up. With a traditional revolver, you’d be able to extract the non-damaged cases and at least stay in the fight, assuming you had a way to load single chambers.
The best of both worlds approach would be to use a gun chambered in a rimmed cartridge that’s been cut for clips. Your first cylinder is loaded traditionally, and your reload is in moonclips. Personally, I’d just carry the whole thing in clips, first rounds, reloads, everything. Faster reloads and more positive extraction outweighs the risks of possibly tying up the entire gun with a split case.
One other thing to remember is to maintain your clips. A bent moonclip will really ruin your day, so if you are going to go the clip route make sure you get a clip saver to preserve the shape and function of your clips.