8000kms, is surprising that your ebay downpipe held up that long. But I can promise you it will not last as long as ANY of the half decent pipes. Literally yesterday I re welded a customers down pipe which was cracking around every weld egay fail!
The downpipe is the most important section of the exhaust, it handles the most heat, has the most weight bearing and vibration. It is also the first section of pipe the exhaust gas sees. The KO racing pipe being 2.5 has the smoothest exit section of all the pipes I have seen, it is MIG welded construction, using thick pipe, and thick flanges. As long as you have a 3" exhaust behind it your not going to develop enough pressure in the pipe to require a 3inch pipe. Not saying its not nice, but I prefer a better flowing 2.5 than a cheesy 3 inch pipe just because its 3 inch. The aussie on the other had WAS a well made pipe, I had one for about 6 years of heavy driving 100,000kms and NO issues besides corrosion as it is made of mild steel.
Right now I run my own version of downpipe, 2.5 primary with a separate WG dump section completely separate from the main turbine flow. Best pipe IMO and sounds like a MOFO
Cheers
