How loud or sensitive is the lapel mic?

The lapel mic on the officiant will likely pick up your voices but not "loud and clear". How loud and clear depends on how loudly you both speak, how closely the officiant stands to you, and any environmental noises. If the officiant stands about 2, maybe 3 feet away from you, there is minimal environmental noise, and you both speak loudly and clearly, you will likely be heard. If you are both just repeating vows from the officiant then the one mic is plenty. If you are reading original vows and it's important for you to be heard, we would recommend using the second handheld mic or a second wireless lapel mic on you (the groom). A second lapel mic is $50 and the handheld is included.