I have a few of these Snapware cereal containers that I still use... I like them also but I find that the mouth (opening) is a little too wide compare to my Rubbermaid cereal containers and they do not hold a large box of cereals. So I tend to use my Rubbermaid containers more... also the grip is a little wider so it's harder for my kids to grip them.
They do keep the cereals fresh just like the Rubbermaid containers . They aren't as bulky as the Rubbermaid.
Guess you can't win them all ;)