It needs all the increments. (for example I had a Korg once that jumped from 120 to 180 or something and I needed the tempos in between. Useless to me.)
I use separate metronomes for practice and use a software click for recording. They need to be accurate so what I practice and develop muscle-memory on matches the tracks I'm overlaying.
I also prefer one that starts immediately when I hit it, as opposed to resuming somewhere in between the beats where I left off, or some awkward delay while it electronically detects that someone is actually trying to use it and decides to begin operation, stuttering in late like a drunk/fried drummer. I could just start a band if I wanted that effect.
Needs a choice of sounds also, for accuracy and to avoid abrasive/harsh sounds, and sounds that bleed out of headphones onto mics.
