I only just started with TC vaping and only bought titanium wire.
My mod has a titanium setting and I did some TC fiddling to find its spot where it only lightly browns the cotton if dry burning.
I had a bit of trouble shaping the first coil as you can't really glow titanium. Low power pulsing seemed to do the trick without causing any white stuff appearing. I clean the grade 1 wire I have with pure alcohol to remove any potential surface residue.
So far I'm quite happy using a TC mod and the flavor seems good with titanium. I did not notice any significant change to my kanthal wire.
I have no experience with nickel, seemed tricky to use to me and never bothered with it.