MF skillpath is messed up after the nerf
DISCLAIMER: i'm not saying MF is a weak champion (weaker than Ezreal-Lucian-Corki-Kalista for sure, still better than the others), i'm talking about her skillpath being weird since the last E nerf.
So, after the last patch it looks like Riot wanted MF players to max Q over E-W-Q, well, it doesn't look like they actually succeded in that:
http://www.probuilds.net/champions/details/MissFortune E-W-Q max everywhere
http://champion.gg/champion/MissFortune E-W-Q max is way more effective than Q-W-E max
I can understand the reasoning behind the E damage nerf: it's a utility spell, why would it have alot of damage aswell?
The thing is, it's still probably better to max E first because ever since they nerfed the slow on the skill it has not been a good one point wonder, not to mention almost everyone buys boots of swiftness now.
Her E slow used to be 40% at level 1, now it's 28%...how would you even expect people to max Q over E if the base slow is so pitiful? It goes from 28% to 60%, it clearly needs to be maxed first, whatever the damage is, because the base slow got gutted.
Max Q first: you might as well not have E, 28% slow is just not noticeable.
Max E first: Q deals less damage (not much less, the bonus damage by levels is not that high, and the lower CD does not justify a Q max, expecially since her terrible base damage makes it impossible to buy a triforce), but at least it still applies your passive so it's still usable.
I think the base slow should be 40% or even 60%, but the damage should be 90 at all ranks, if not even less.