I haven't had a phone with Face ID (in fact, my current SE is the only one I've had with Touch ID), but I'm not anxious to move to it. I don't know where this falls among your UX factors, but I feel more in control with Touch ID. I feel like I'm the active participant and the phone the passive one. It feels to me like with Face ID those roles are reversed. The act of reaching with my thumb and hitting the home button feels very purposeful to me, whereas the act of looking at my phone is something that happens all the time. Though I don't know what it is like in practice, it feels like something that could happen accidentally. I could hit the home button accidentally in pulling the phone out of my pocket, too, but at least the phone is not a participant at all in that, that's all me. With Face ID the phone itself is complicit too.