i have a ceramic coated 4-1 header, works fine for me, i heard that the ceramic coating can crack after a while and not work as well as it did in the beginning while stainless steel isnt supposed to wear down, ive always just used ceramic because i think it looks better ( i hate alot of flashy shit under my hood) but i guess for most street applications theres no wrong answer here, i think ceramic coated headers are meant for race applications where you need that extra cooling, if your just racing the local drag strip on a weekend or something you should be fine with either, id go with what ever is cheaper