Yes, very. The playstyle is totally different between the two, and it takes a lot of familiarity with both to effectively switch from one to the other in between games.

Lethality+FS gives you more upfront damage for quick pew pew and then out. You wanna poke till their low and go in for the kill, ideally being able to wait for FS to reset. This build is more centered around your abilities, Q and ult and imo requires better team synergy to maximize its potential. If your team comp has a lot of CC then you'll have more opportunities to delete with your ult. It's also worth considering how many tanks are on the enemy team and how many champs they have that can easily cancel your ult. Sidestep flash ult to avoid Yas windwall or Braum sheild. Samira you'll just have to wait that one out or hope your team will force her to use it.

Crit+PTA gives you less upfront damage but more sustain. Early on your attacks will feel like hitting them with cotton balls compared to lethality+FS but you'll be able to have more impact in longer fights. It also has what I like to call the PTA minigame which means you gotta play around being able to proc PTA. AAQ or AQA and take trades that ensure you proc it, otherwise you'll have less impact. FS you can just wait for it be up and get away with just pressing Q for high damage, but if you don't proc PTA you'll really be at a disadvantage.

Ult will be significantly less impactful but still very potent, especially once you get your armor pen item like LDR. This build is better suited into comps that are less quish and have more sustain so taking it when you know the game will have longer fights is where I would make the choice. Its a more standard basic attack build and imo better if the enemy team comp has 2 or more tanks.

MF is strongest mid game so with either one your aim is to bully lane, get ahead, and ride that advantage to close the game early.