To be honest, I haven't played Fiora, so it is difficult for me to really judge, but in theory it actually looks like the new Fiora's kit is pretty strong. She has the potential to gain health, movement speed, and AD scaling % max health damage (WTF!?) every time she strikes a 'vital spot,' which appears to be a quarter of their hit box, so fairly easy to land. The heal gives her great sustain and the movement speed bonus will help her to reposition to break the next vital spot.
Her Q has great AD scaling as well, giving her a great engage/disengage. It sounds to me as though if it is used properly it practically guarantees a vital break, as well as decreasing it's own cooldown.
Her W scales on 100% AP, which is also insane. It does look as if this may be among the more difficult abilities to land, but it also blocks incoming damage, and potentially even stunning, which just sets up her to further stick to the target.
Now E, flat attack speed increase instead of stacking for the next two auto attacks. It does not say if there is a time limit but then for those two attacks to slow and then GUARANTEED CRIT!
Now her Ult. .. I see this as being the biggest difference. I think taking the 'random' aspect out of her ult gives her significantly greater kill potential, and the resulting heal gives you a better ability to gain any lost health back for your next engagement. The fact that the radius is so large means you can even be moving toward the next engagement while still gaining HP. The fact that it heals allies does help your team by encouraging support or ganks, or even help when Fiora ganks/roams. I highly doubt that this will make Fiora into a support because she still has such high kill potential.
To be honest, this rework is kinda making me want to know get her. The biggest issue I see her having is having no abilities that directly help with wave clear aside from her attack speed buff. Benefiting so strongly from AD and attack speed will definitely help with this, so I don't see it being an issue. 
would help solve this and work very well with her high mobility.
