I use a metronome in at least 75% of my practice. There is no better way to practice technique than by slowing it down and playing it perfectly in time, especially with a subdivided beat so the rhythm within the beat is exact. I didnt practice with one when I was younger and I can tell. I dont think you should use one when actually playing a piece, like your solo, but to tear it apart and clean up the technical passages you need one to ensure that what you are playing is exact. Playing in an ensemble if an entirely different thing, but using a metronome in your personl practice can do nothing but help your internal pulse and ability to play in time with others. And thats about all i have to say about dat. lol.