1. Is always too low.
  2. Doesn't properly lock and is too far from the door to wedge a foot preventing unwanted access.
  3. Has the paper stashed somewhere unexpected if it exists at all.
  4. Hits the exact spot on the back of the knees where you lose all feeling in your legs and can't walk after getting up.
  5. Has a gap between the bowl and the seat so that male urination from the seated position leads to damp jeans or a pool on the floor.
  6. Never flushes the way you expect it to.
  7. Leaves your dog ends floating as accusatory evidence.