Yes. Having used both, ultrasonic have better accuracy and much faster unlocking speed. Works better with wet fingers in my experience. Also when you unlock your phone at night, you won’t be blinded by bright white light.
But it is not an absolutely essential feature. The other will get the work done in budget to midrange phones.
I am not self hosting an LLM, but running on my laptop with Alpaca. Google’s Gemma 2B. On my hardware its pretty slow, but kind of gets the work done. My hardware is getting old, need to upgrade soon.