Really, I agree with 95% of what everyone is saying, and the other 5% I’m not sure any of us can be sure of.
There is no question there will be an improvement in performance. Less weight, less inertia. No one can argue with that. So, don’t misunderstand me, I’m not even going there.
The comparison with the racing world doesn’t matter because they do inspections and tear downs all of the time. Racers aren’t looking for durability over 200k miles. But, Justin running a JHM pulley for 8 years is good info, as is cars running with failed dampers.
In general, performance mods are sold to people to keep there cars for few years and then move on to another car. Who really knows what the long term effects are. An oil analysis won’t tell anything, as it is portrayed as a crank stress issue, although perhaps minor. Could be a case of German over-engineering, who knows.
Really, what it comes down to this question for me: has the JHM crank pulley been proven to minimize the vibration that Audi thought was problematic enough to use a more expensive damper? The manual talks about stress reduction on the crankshaft, and I’m not in the position to disagree, so for me personally it’s not worth it. I’ve done this dance in the Porsche world with mixed results, so I’m less enthusiastic now.