I had high hopes for them. The idea of a two piece wireless XLR is great, but I'm not sure it will ever replace cables. They work, but expect lots of crappy audio and high hiss if you want to go to the DI block -> Transmitter -> Receiver -> Mixer. If you simply want to transform your SM58, get ready to compensate by boosting your mixer (with noise). I have several 5.8GHz wireless guitar gems and they work great. I'm not sure why the technology isn't translated to them. Battery life is good.