Quietness is a quality easy to overlook until you find yourself reluctant to use it for fear of waking up everyone in your household/apartment building/surrounding neighborhood.
I used one a million years ago when I was a teenager and I hated it because it legit sounded like a lawnmower. Are they still so insanely loud?
I do like Waterpick, because I had a good experience with their customer service. (I messed up the travel sized one by letting the batteries leak out in it, tried to purchase a replacement battery door and they sent me a brand new one.)
I have a portable and a regular unit.
Waterpik is a great company.
I have a few of their products and one had an issue, I called them, immediately got a human, and had my waterpik replaced in 3 days.
It was an absolutely refreshing customer service experience, no chat bots, no phone bots, not complicated phone menus, just a ring and a hello how can we help you.
Love Waterpik.