I've heard the same. In regards to Ayamine's post though, I think it should've been better researched/thought out before it was posted.
Tia is actually better at staging than at PvP in my opinion. Your target(s) is much larger in Stages than in PvP, harder to miss. Tia has several AoE skills which would be difficult to use in PvP due to long cast times, not so much an issue in stages. Tia's primary attacks/skills have far less hit width than Sieg's and Dainn's, making it difficult for low skilled and unskilled players (hit and run skill spammers?) to use her in PvP, while in stages, it might be passable.
"If someone asks you whether or not you're ticklish, it doesn't matter what you say, they're gonna touch you. If you don't wanna be touched, you gotta say something like, 'I have diarrhea. And yes, I'm very ticklish.'"