both are used for temp control ni200 is softer than ti making it harder to maintain without damaging when rewicking.
ti (my preferred wire for tc) is stiffer easier to wick without damage has a higher resistance per foot from what i have seen and in my opinion i notice almost no flavor/vapor change from kanthal to ti which i like the warmer
vape.
this is all what i have seen and experienced in my opinion not a by the book response as with
vaping in general all is subjective