Blue side wins more, but I can't remember the exact statistic.
I find it harder to dodge/land skillshots on purple side because the UI at the bottom of the screen is in the way and the camera angle just feels awkward.
Just sayin but ive never had a problem with playing either and i prefer top over bot just because of the way jungle is in top map. as for camera angle i just play unlocked/locked so i unlock when im engaging so i can see the skill shots and the skills