As much as I love SG Janna, I'm going to have to stop using it.
This is about the Star Guardian Janna skin affect gameplay, so yes this is the right board.
SG Janna creates a huge amount of noise that the default skin doesn't have. Honestly all of her abilities are more flashy and noisier, but in particular her Howling Gale is especially effected. Default Janna doesn't make hardly any sound when she places her gale. You can barely notice it until it's coming towards you.
SG Janna's Q has some of the loudest, most distinct SFX in the entire game. On other SG champions, it's not such a big deal, but Janna's Q is different. You can't just double tap Q and be effective, you have to allow it to charge up. All the noise and the brightness of it makes it easier to dodge. Assuming you're in a 5v5, 99% of the time SG Janna's abilities are going to be the main thing you hear and see. It's REALLY bad. https://youtu.be/m40BisZsth4?t=1m50s
Please at least fix her Q. Her other abilities can be as noisy as they want to be but her Q has so much unnecessary counterplay with this skin. While you're at it, please give the same treatment to forecast Janna. These skins are pay to lose right now and I feel bad using them as well as feeling bad using the default skin when I paid for the skin already.
tl;dr SG Janna is an unfair disadvantage for the team with the skin.