I've had my Hookers on the car for better than a year now. The car sat last winter in a storage space, hauled it through the rain and raced it all year this year. There's no rust on my headers except in the places where I scratched the coating off installing them.
I'm very pleased with the power. I did have to go through some hassles to get my TTi X-pipe to fit because the collector on the header was rotated differently than TTi is set up for (Hooker's fault, not TTis).
However, that was a small price to pay for the cash savings, and the fact that the TTis have horrific bends in the tubing at the cylinder head flange. On the set I had, a couple of the tubes necked down to about 1" diameter, right off of the cylinder head, which is the worst place for it.
I'm convinced that the TTis do a better job with ground clearance, but I'm also positive that the Hooker's make more power.
Again, if I had it to do over, I'd buy plain headers and send them out to be coated instead of buying precoated. BUT, the precoated darksides are holding up very well so far.
Steve