Bought the new Legendary Anivia skin - and now I could never go back. It looks amazing in every way. I've always thought Anivia's basic model and effects needed a reskin, as at the moment she looks like a blocky, bright-blue mess that lobs oversized snowflakes. :-P
Now with the new skin I find I no longer need to wait for any potential rework they could do, because the attention to detail is superb. It kind of sucks that it takes $20 to make Anivia look good, but there you go.
Anivia was one of the first champions I came to really like. I disagree with this general assumption floating around that if there's an Anivia, she must be mid - because I find she's a versatile fighter in any lane. If anything, she can use the top/bottom brushes to her advantage to launch unexpected flash frosts, making her even more effective in those lanes. Then again, I've never really listened to the globally established metas, because a lot of the time they're wrong, and are established by people who believe they know the only way to play a champion.
A good tactic is to time your Q's with your autoattacks, as the animations and spell effects look so similar that you can catch your opponent completely off-guard.