Headers love to rust like manifolds love to crack. They all have their evils.
I just dont see enough advantage to offset cost since you gain no performance over the 08 manifold for far cheaper
There is a maximizer header on ebay for a bit cheaper as well.
Well, if they're stainless like they say, they shouldn't rust. Or at least, not much, if it is cheaper stainless they still will sort of. Also I wonder what the welds are - I've seen cheap "stainless" stuff rust apart at the welds because those are regular steel. That's always fun.
I have regular coated headers on my Camaro and yeah they have some rust just from thermal cycling and dampness. Ideally, whenever I get to a V8 swap, I'll throw stainless headers on it and avoid that issue altogether. Just, $$$$