We bought two a year ago to replace some older ones that were becoming unreliable for Sunday morning music service and found them to be a great quality mic with excellent wireless range and a good value. When it was time to replace two more, there was no question we would go back wtih the same ones. We had the SM58 in a wired configuration for another application and found them to be a good quality mic for vocals. Having 4 on the same band has not caused any issues, nor with our two headset mics. I am a little concerned with the plastic battery compartment cover, as sometimes nervous performers tend to twist the battery cover, but we have not had a cracked one yet.