Janna is mad OP in dominion.
 

She was one of my top fav champs when I started in S1 and I decided to dust her off after...3-4 years not touching her. CC for days and mad quick (low CC) and them kites oh man them kites. My kites bring all the darius to the ganks. Wanna try capping my turret? No fck you have a tornado, no have 3, tornadoes for everyone, tornadoes, tornadoes everywhere. She's the queen godess of "kocked up" if you know what I'm sayin *wink wink* I'm of course talking about TORNADOES.

Now that I got the trooll speak out of me, seriously. I'm prolly at mid elo but I found if I talk **** all game they will chase you for days. Seriously I had a Darius and Alistar chase me for literally 3 and a half minutes before I suicided into their turret at no kill for them. My teammates were too terrible to take advantage of their top 2 threats MIA and just decided to camp the 1 turret we had but hey I got hearty laugh out of a 3 and a half minute kiting fest Is she effective at more competitive levels in dom or am I just taking advantage of my inability to break into higher elo?
Bonus Content for great victory: http://www.youtube.com/watch?v=FrsTE1vpoXM

Janna is good, yes. But I wouldn't put her above Lulu in terms of OP

I don't actually think she's OP i just titled it that in response to the Akali necro that was at the top when I made this. I do find that she's a game changer when used right. Becasue who doesn't want to give pantheons free BF swords?

Janna is only good when the enemy team derps around and chases you forever

most good teams will work on points and let you go, especially your damage output is meh

It's not her damage it's her CC she brings which is a lot and it's all on low CD. her damage is laughable unless she builds straight AP which is bad, very bad. also

Before her nerfs she used to be considered top tier along with Lulu, she's still super effective specially if you duo with a good AD Carry, bonus points if the guy is great at Vayne , late game your combination will wreck any one in team fights as your combined CC and Vaynes kit will leave you both untouched.