The inconsitencies of suppliers/factories and stylists. The units are never the same nor the quality and the same stylist that's been cutting your hair for years, suddenly can't do it right!

The fact that I am a perfectionist probably does not help!

The fact that units don't stay great looking for very long.

After 30 plus years I still do get excited though when a new unit is being cut in and styled. Beats being bald any day!