I've been using the CM-311A for several years and I love everything about it other than it's comfort. The vocal quality has always been superb, no feedback, no breath sounds when properly placed, and the freedom it provides is incredible.
For a while I had a Samson AX2 Wireless system for the mic, which was probably the best wireless device I've come across in years. Unfortunately, Samson stopped making the compact receiver for that model and went to the larger, double antenna type, which takes up too much space. The biggest mistake I made was selling the AX2s (I had a pair of them) to DonM and EddieS--they won't sell them back to me.
PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)