i don't use it for rhythm, for that i read the music, but i find it helpful for speed work, i.e. working on incremental tempo increases (those smaller than I can easily percieve) for example, increase spead by one click per minute, nailing the passage, increase by one click per minute, nail the passage, increase again , etc etc. not super efficient but very helpful for memorization and finger kinetics/mechanical learning.
I wonder how often you guys use the metronome (if at all) and for what purposes exactly ?
the incremental tempo increase method can cause pretty significant problems. There is a very real danger of learning a motion that works for a slow tempo but will fail at a higher tempo. And, you will have practiced the incorrect motions hundreds if not thousands of times before discovering that they fail at a higher tempo. It is incredibly ineffective if you fall into this trap - one of the main reasons a teacher is important.. aim to identify effective fast tempo motions before practicing at a slower speed, then practice fast motions slowly.
But when just beginning a piece, if you don't know the notes well enough, it is best to practice 'slowly', hands separate. I do have a teacher, and she suggests doing this when starting a piece. And, when I practice, I go back and forth between faster and slower tempos for the same reasons you mentioned, as it helps me get an idea how both ways work.