The Sennheiser EW100-G" is an amazing piece of gear and I love it to bits. I wouldn't consider using any other sort of mic now as it gives total freedom of movement to a singer who, like me, likes to dance around a bit when performing. It means that you can walk to the back of the stage to pick up and instrument standing there and talk to the audience at the same time, giving continuity of performance.
As Anahata says, soundmen think it is great as it is so easy for them to set up and use. And it is one less cable to trip over!
Mary