I've been playing her for a while now, and I really like her kit and her concept. However, so far i havent won a single game with her, no have i lost a game with a Taliyah on the enemy team. Her laning is ok, she doesnt win or lose lane. The best you can do is come out even in lane, and then try to roam. I feel like she's an amazing play maker, which is awesome if you're team is ahead. However, if you're team is behind, it's really hard to carry as Taliyah, no matter how fed you are because your damage is laughable compared to other mid laners. Her Q is very limited because of the 3 minute passive that covers the lane after a few uses, reducing your damage output and dueling/trading potential. Not to mention it's already hard enough to land all five shots. Moreover, her E W combo while nice, is still very hard to land and eats up a lot of mana.
All in all i think she's a cool champion, and i'd like to main her, because she has amazing potential, however, i do think she needs a buff to her damage. A reduction on Q's passive would be nice to improve her dueling/trading in lane. Also, i think she needs a combat aspect added to her passive, like a damage buff if she's close to walls, because as it stands, her passive is useless aside from helping her roam faster.