Every excellent musician has been a slave to a metronome at one time or another. It's one of the tools of the trade, and essential for building one's rhythmic accuracy, for few people care to listen to a group of musicians who are marching to the beat of their own drummers.
I own several different metronomes, but this one is from my House of Cards deck that I feature every so often in my Blips. This Seth Thomas is of the wind-up variety, and a true classic. As a young musician, I viewed it as an instrument of torture. As I matured, it became a opponent in the musical game of speed, for being able to perform a piece of music at a "Presto" clip, takes hours of careful practice at lower tempos.
Once you master a slower tempo, you gradually lower the little weight, and pick up speed. It may appear tedious to some, but to the virtuoso, it is a challenge that inspires perfection.
Accuracy in rhythm is paramount to reaching musical goals and adding dynamics and other expressive embelishments to a performance. Of course, turning the machine off and learning to feel the rhythm deep in your soul, is the ultimate rush for those of us who have strived to be the best.
Keeping time, biding time, or stepping in time, the metronome is a musician's best friend. For better or worse.