Does anybody use the buckets with nipples at the bottom that hang on a fence? What are the advantages and disadvantage vs. the nipples with tubes going to the bottom? Are the bottom-nippled buckets leaky? The bucket I am talking about is this: http://www.hoeggerfarmyard.com/xcart/Rhinehardt-Nipple-Multi-Kid-Feeder.html. There are other types of nipples you can get with it as well.