I've had the DDM RIS since 2009. I can't really comment on any power gains since I added it at the same time as an exhaust system. My only gripe is that it did start to show a little rust on the scoop after a couple of winters. That was with weekly spray downs during the winter too! I'm happy with it, but be sure you're cleaning it meticulously during the winter if you live in an area where they salt the roads.
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