Never heard of either of those.

i just have food and water containers that look like these thingies
http://www.theenvironmentalstore.com...ners_small.JPG

but of course my dogs containers are a lost smaller then that,, and the jugs are turned upside down,, and fill into a bowl things.. and as my dog eats or drinks,, after a certain levle of food or water my dog used up, the jug automaticly depsenes food or water out.

i do change his water whenever i remeber to though.