Back to mics...
Tonight, just as an experiment, I used my Shure SM35 headset mic, all night. It did just fine. My vocal control was just fine. I used it part of the time with compressor and part without. It does better with the compressor, as would be expected.
The Crown has built-in compression; the Shure seems to not have it, but no matter, my keyboard vocal processor does. The Shure costs $100., about a third the price of the Crown. I prefer the sound and feel of the Shure. That doesn't make it better; just better fit for me.
The audience couldn't care less about which mic I used. I will go back to the handheld mic next time because I prefer it, NOT because I don't have "vocal control". I don't want to have it "on" all the time. Don't want to have to move it or mute it to cough, clear my throat, take a sip of water or speak privately to a customer.
I can see it would be good if one were moving around a lot or dancing. I don't do either when I play and sing, so that is not a factor for me.
If you ARE in the market for a headset mic, I recommend the Shure SM35 as a real bargain. It is fairly comfortable and can be used wired or wireless. It does require phantom power, which the Korg PA4X supplies.
It mic has the same processing as the Beta 58, and with e.q. can sound pretty much as you want it to sound, as can just about any decent mic.
Experiment over for me. I'll keep it around in case I ever get in a situation where feedback might be a problem.