I did the same thing with my five gallon buckets. I've got peppers growing upside down but I have herbs or broccoli growing in the top. So far it's working out very well.
Never tried the topsy turvy thingy but last year I did an experiment with five gallon buckets hanging from the roof of my greenhouse. The tomatoes I planted in them did not do as well as the tomatoes planted in the ground. Look at the root systems your tomatoes put out and you'll see why. On...