I like third-moon clips. They only clip two rounds together so they aren't the greatest for a fast reload, but with them you can store 50 rounds clipped together in one of those handy pistol ammo boxes. Their main virtue is that you can easily clip and unclip ammunition / spent brass without tools.
Full-moon clips are certainly useful if you want a fast reload. You can buy special boxes to simplify carrying clipped ammo to the range. You can buy leather carriers that attach to your belt for them as well. I've never tried them, but a company (Rimz?) makes plastic full-moon clips that can be loaded / unloaded without tools. Search the web if interested.
Half-moon clips are a little fragile. They are easily bent and may be hard to straighten out if you want to reuse them. They were meant to be used once and discarded.
