Expertise:  Upside down left handed guitar playing

Experience in the area
I have played an upside down guitar for the past 30 years. Although it is somewhat unique, there are many distinct limitations as one becomes more serious musician. Many bad habits (partial chording) are picked up because many finger positions (alternate chords included) are totally impossible. Picking stings requires the "pinkie" to carry the bass line. I took classcial lessons for 12 months or so and it just became a physical impossibility to duplicate the "proper positioning". I am able to play several difficult pieces, but I do have to "cheat" to complete them. My advice to all new guitar players (less than 3 years experience) would be to restring the instrument properly. The reward will be there down the road. We probably would never have heard of Hendrix had he chosen to play upside down and backwards.