@coryvp
I'd like to see a photo of those buckets if you can manage it! And, for my own info, what is a 'food-grade bucket'? Are regular paint buckets not food-grade? What makes one not food-grade? Might not matter if they aren't used for food, I guess, but I don't know the difference.
If the tomato plants thrive, that sounds like a good way to grow them. You could get them going earlier and keep them protected from a late frost and maybe protect them from excessive heat by moving them around after it gets really hot in the summer. Also, they shouldn't have nematodes or soil diseases grown that way, would they?