This is a thread for pointing out developer or vendor claims that have no backing evidence, and testing to see whether there is any truth to them or if it's just bullshit.
I'll start with one. I was looking into Redox OS and found out they have their own shell called Ion. In the official documentation for it, they make the bold claim that while it doesn't strictly follow POSIX, it apparently, "also offers a level of performance that exceeds that of Dash". That's quite an impressive claim, although somehow I highly doubt they could pull that off.
https://doc.redox-os.org/ion-manual/
So if anyone with more knowledge of shells than I could come up with some kind of benchmark to test these two against each other, we can see whether there's any merit to their claims.