I have tried most of the mics you guys have mentioned. The shure sm58 is very popular but not hot enough for my tastes it took a little more gain and loss of headroom for me. But on the road, I do see more of them than any other mic.
I've used the EV 267, EV 367(for my wife), and EV 767. I really liked the EV line, good rugged mics that travel very well and sound good.
I also have the Countryman E6. Jeff you're right its easy to forget it's even there. Its a joy to use and almost invisible. I even had people come up to me after a performance and ask, "How could I hear you so well when you didn't even have a microphone." LOL. And it is very easy to play with a headset on, no mic stand in your way.
But after we bought the rest of the vocals Sennheiser wireless mics, I tried one and found that I had more bottom-end and depth with these handheld than with my E-6 earset. So now I have 5 of the Sennheiser wireless EW 835 Mics in my rack. They work very well!
Richard