There's been a lot of discussion since that post. No argument at all about what people find annoying (or don't mind). But a few of those points are demonstrably false...I'm with you, the most annoying feature ever. Spend a hundo to get a autostop eliminator for my wifes new Bronco that way you don't need to turn it off every time you re-start
Both the starter and battery for a car (specifically an Mk7 the 2.0CR and 6MT) equipped with start/stop are different. Parts looked up for ROW vehicle, since the Mk7 TDI was never offered with it in North America. I suppose we don't know the real difference between the starters, would need to find a spec sheet from Valeo, but something is not the same because they gave them different part numbers. I'm sure it's just going to be a different chemistry battery, not a big deal but spec'd differently for cars with and without start/stop.
I don't expect the flywheel is different, although I didn't actually look at the parts breakdown for transmission with and without start/stop. At some point this weekend I might have a look. Turns out the 6MT for start/stop has the case drilled for the neutral position sensor. So it's unknown whether that's the only difference.
Fuel savings is easily measured, and has been... see the video posted in an earlier post. Of course it will vary between engines, and the savings on fuel may or may not offset the lifetime cost (for the owner) of replacing other components required for the system. But as a singular measure... an engine not running is not putting out exhaust gases, and also not using any fuel.
In the short test mentioned in that video (city driving, light and heavy traffic, 2 liter gasser) they saw between 4 and 8% MPG increase. If we call it 5% and assume a modern 2L gasser gets 25 MPG that moves us 26.25 MPG. That's 1,250x the increase alleged (estimated?) in the post you quoted .
And carbon credits? Are those offered to manufacturers for having start/stop vehicles in their lineup? Is there some way I can get some carbon credits (to sell) If I finish this retrofit? That might convince me to drill the hole in the side of my transmission case. How much driving do I need to do to generate, or rather realize, 1 ton of CO2 savings to earn one of those sweet credits which are worth $30/ea here in California. And is there any way I could sell them in the EU where they're about $100/ea right now .