I purchased two of the 2 gallon waterers with the little peck nipples. Both of my units ended up leaking. I contacted customer service and they responded fast and offered replacements and even offered to let me try another type if I wanted. Awesome customer service!
I will say that these two gallon buckets can't take much movement. I have 20 chickens and was I move them around my property with portable fences. My wife wanted to try smaller buckets because the 5 gallon ones can get a bit heavy. We transport our food and waterers in a yard cart and these small 2 gallon buckets couldn't stand up to being moved so often. They developed little cracks around the holes for the nipples.
Rent a coop asked if I would like to try the 5 gallon and it works great. The plastic is a bit thicker and seems like it will hold up to how we use these.
I tried the little auto fill water bowl style as well and they way they come drilled won't let you set them down, the bowl is below the bottom of the bucket, but if you are hanging them and filling them in place, they should work great.
I will be looking to Rent a coop first for all of my chicken needs!
Tldr: Great customer service, buy the 2 gallon if you will keep them stationary, but the 5 gallon if you plan on moving them around.