From what I understand, it seems like Dizzy is doomed to be terrible in AC. In Reload she was B tier or so (not sure on this, I started playing right around when Slash came out and only played Reload for a month or so, but I do recall hearing about Dizzy winning tournaments here and there, something I have never heard of since Slash). Then in Slash she got a few new things, but her negative changes overshadowed them and she went down in tiers. Now in AC she once again gets a few new things, but then loses more important stuff (fish, even lower defense). Combine that with the fact that most other characters seem to have improved in AC, and that sounds like a recipe for a terrible Dizzy.
I really don't understand the reasoning behind her AC changes; it seems pretty apparent to even a scrubby player like me that she got hosed this time around.
edit: I don't mean to sound like I'm complaining or anything, I just want to be realistic about what it seems everyone is thinking.