dab67531_sadvantages___Bounce_Metronome__Advantages
[Disadvantages] You may miss notes and play badly when you play the difficult passage at speed along with a metronome - and repeating just reinforces that bad way of playing Take care when practicing difficult passages with a metronome that you don't reinforce your mistakes. Spend some time focussing on the difficult passage and get it right at speed before you play through the whole piece. It can help to play it many times faster than needed, then once slower. Or to play it slowly and gradually speed it up. You can use either or both approaches. See below. Once you can play it fluently at speed every time, continue to play it slowly as well on occasion or the fast version of the piece may deteriorate and become sloppy. [Advantages] 
Most musicians have a tendency to slow down at difficult passages. The metronome helps you to make sure you play them at tempo
Metronome Advantages and Disadvantages - Bounce Metronome
Advantages