I really like the ultrasonic finger print sensor on the 10+. I came from an S9+ and I never really liked the sensor behind the phone. I always felt like I was searching for the sensor and smudging every lens in sight. I don't think that was a good place for a fingerprint sensor. I'm much more happy just placing my finger on the screen in the right spot. Does it work all the time? Well, I think the sensor on the S9+ did work more often but the Note 10+ one isn't terrible. I have large hands and I work in a factory so my hands tend to be dry, dirty, and scratched up. This does not lead to good results with ANY fingerprint sensor for me. But, the N10+ sensor doesn't really annoy me too often. I love not having to search around the back of the phone so it's all cool to me.
As for face unlock and iris unlock. Well, never use face unlock, it's terribly insecure. Iris unlock was probably more secure but since they switched to a little punch for the camera there is no room for an infrared iris scanner so I can understand why it was removed. So, I don't care. If I want biometric unlock the fingerprint sensor is "good enough" for me.