I went in for my second treatment last night. There was a different tech, who said we should go up in power because the first one had been too soft (which was a concern of mine).
Heck, did it hurt this time. I couldn't hold still. She had to stop a couple of times to let me take a breath and cry. I could smell the burnt hair and even hear the sizzling. She felt horrible when I started to cry, because she had never had someone cry before, but she only had one other trans patient who was getting a different area, with sparser hair.
She thinks the extra pain was not because of the higher setting, but mostly because of something she hadn't realized at first: that she was using a machine with a bigger head than the last tech, so she was zapping a larger area.
Unlike the first time I felt the heat on the first passing, but also I had reddening on my face, which I didn't have last time (one sign it was too soft), and as soon as I looked into a mirror I noticed a difference. It's like some hairs were vaporized or something. For me it was totally worth it. She had me book the next treatment with the smaller head, but she referred to it as "the slow one" when talking to the receptionist, so I think I'm calling in and changing it.