Been using them for years now as a fixed point at the end of my tapered leader and simply attach my desired tippet directly onto the ring. As long a leader as I can handle for a single dry, or around a foot to first fly if fishing a 'team',
Simple and easy to use, no hinging issues and very strong. There are types that are more a round cross section if you feel the 'flat' type might cause breakages, however I've used both and have only had one cause a problem (trophy troot lost with a breakage, on inspection the ring had been damaged, probably hit off a stone, and had a tiny sharp edge on it)
One thing you will certainly get though (very very occasionally) is fish taking them, I think they might hone into any flash given off?