That's not confirming it optimal at all. Your personal experiences aren't everything. Even if that build works for you, there's a reason most Fiora players either go Hydra>Cleaver or Tiamat>Trinity>Hydra.
On Phantom Dancer, I just can't see it. Attack Speed is okay but not super useful - AD, CDR, and Pen are all more useful offensive stats, because on Fiora the goal isn't to sit and auto someone to death, its to dance around them, doing the majority of your damage with Q and Passive. Crit is flat out not useful - you don't need it to kill squishies, and more AD or Pen is better for killing tanks. Your E actually prevents some benefit you could potentially get from crit. And the movement speed and passive, while both very useful, aren't really good reasons to buy them item over something that provides more damage.
On Sterak's, it's alright but I certainly wouldn't think its the best defensive item choice for Fiora. In most games, BT and GA are enough for defense (though of course you could sell GA if you're full build and its on cooldown). Getting a primarily defensive item second actually kind of wastes your lead, if you have one. While the AD it provides is useful, the shield isn't actually particularly good on her, because A) it requires you to lose a flat amount of health thats ~80% of your HP to trigger, and B) the shield is based on maxHP, which you aren't really itemizing for.
Better choices for either of these items would be Maw, Death's Dance, and Mercurial.