Two things I would like to add as a CON for overhead lamps:
1) the lamp itself is cheap, the bulbs can be very expensive, and do not last very long. They are very sensitive to ANY sort of knocks or bumps. The filaments go very easily, and it can cost $20 or so to replace the bulbs (where I live at least)
2) I would absolutely not recommend using them in a household with small children, or cat(s). If a child yanks on the cord by accident and knocks the lamp over, or if a cat knocks the lamp over on to a carpet, you will have a fire, and QUICKLY.
But a very good, informative write-up. I will for sure be sending future customers to this thread so they can make the decision for themselves!