I can't see a Milltek lasting 10 years / 100K+ miles though. Thin walled pipe and cheapy welds don't tend to last well.
stainless???
There's stainless, and there's stainless
I had a Milltek on my old Corrado and the welds broke off in the key areas, the flexis were low quality and the pipes went brown and rusty within 2 years. Not rust as in flakey mild steel rust, but it's just a low quality, thin walled stainless which is pretty cheap wholesale.....but they charge the public a fortune for it.
After that I imported a Borla stainless system from America and the quality difference was stark to say the least!