I say this as a lover of speed. I have worn out many metronomes in my life, not from throwing them out of frustration, but from use. I work meticulously to achieve my ambitious tempo goals and then exceed them by 10% to ensure ease. Yet all too often I get caught up on faster and forget there is more to music than speed. Many times there is a lot less music with more speed. Finding the balance between a tempo with brings life and one which crushes music is a constant struggle.