I didn't start noticing the buzz in TC mode until I read about it here and now I can't stop hearing it 
Anyways, I've been using my M class for a week now and it's been great. I still don't understand the nuances of TC though. I can't even tell the difference between 230 degrees and 420 degrees F. I never hit the cutoff temperature I set and I sometimes get dry hits. They aren't "I WANT TO DIE" dry hits of burnt cotton, just dry hits where I think liquid hasn't wicked properly. I guess that could be a product of me chain vaping more and/or the thickness of the liquid since I'm using a Billow. I have noticed that I've been going through liquid like crazy since I sold all my other mods and switched exclusively to this device.
Anyways, I've been using my M class for a week now and it's been great. I still don't understand the nuances of TC though. I can't even tell the difference between 230 degrees and 420 degrees F. I never hit the cutoff temperature I set and I sometimes get dry hits. They aren't "I WANT TO DIE" dry hits of burnt cotton, just dry hits where I think liquid hasn't wicked properly. I guess that could be a product of me chain vaping more and/or the thickness of the liquid since I'm using a Billow. I have noticed that I've been going through liquid like crazy since I sold all my other mods and switched exclusively to this device.