Yeah good luck reaching that point.
Her Base AD and AD per level took a giant hit, not to mention less AD from masteries. Her early game now seems like it takes way more effort to succeed for much less reward. She can't 1v1 anymore, she's not even capable of 1v2ing with the changes, and will take longer to win a 2v2 (longer than the other side, who just focuses someone down to quickly make it a 1v2, which again, she can't win.)
Maybe I just can't find a way to play PBE MF right, but as someone that mains Miss Fortune on live with great success, this is basically a different champion and I can't seem to make her work, and I feel very alienated by the changes. I frequently would end up in 1v1s, where even ahead, I can't win at all, and not even a nearby minion would help change it. I can't make it to late game since the other ADCs have much better/easier early/mids and burst me down. Her level 6 pbe ult feels way worse to use at the time I get it than on live. As for her passive, you are basically splitting your attacks and it takes longer to kill either target (effectively halving your attack speed, and your dps plummets if one or both of them split off.)