The reason I choose the round one is because it sits on my coal pan from the ECB just right. This gives me an ash catcher and raises the coals off the floor of the drum about 4". If I had a metal 5 gallon can I would cut the bottom off for an ash catcher. Hmmm, maybe I can find one.
In the spirit of the UDS, I am trying to use what I have around the house and buy as little as possible.