My experiences mirror most of the folks here. I have used the rope plugs, BMW plugs and the Stop-n-Go plugs. Only one of those three has failed me. Yup, that would be the Stop-n-Go. Failed me two times and also failed on a friend‘«÷s tire when we were riding together.
The BMW ones work, but they are a real pain to insert; I don't carry them anymore. I carry the rope and glue ones and a Dynaplug kit I got last year. I have not had the chance to try the Dynaplug yet. As a matter of fact, I hope I never do