Glad to know I’m not alone in this. I’ve seen everyone completely praising FaceID as a perfect replacement and I’m like “are we using the same phone”? Lol. It’s good enough. But I’ve definitely had situations where I’m waiting an extra second for two for it to authenticate before being presented with my home screen.
I've had no real complaints with FaceID, though I have had a mild learning curve (making sure I'm looking at the screen and have the screen pointed at my face) -- but don't misunderstand, it has worked well for me. It is a tad slower, though it does help if you start swiping up before it unlocks. OTOH, it is far more convenient to use notifications, I can now select the notification and it takes me directly to the app, no more fumbling with TouchID in between.
And this is the same, for me, with apps that use TouchID. For me, I had to wait until the app said to put my thumb on the sensor (or else TouchID often did not work); now it is seamless, the app starts, uses FaceID, and I don't have to do anything; so it is as fast, if not faster for me. Same with Apple Pay, the one time I've used it; I double clicked the power button, FaceID authenticated, and I was ready to pay before the cashier had finished.
To go back to the OP; I found this YouTube video interesting; he did a battery life comparison between the Galaxy Note 8, the OnePlus 5, the iPhone 8 Plus, and the iPhone X. For those that don't want to watch the video, the iPhone X lasted over half an hour longer than the iPhone 8 Plus (and about 28 minutes longer than the Note 8), and finished second, by 13 minutes, to the OnePlus 5.
https://www.youtube.com/watch?v=1Mtiia37kdc&t=1s