(The post isn't comparing Android 2.2 to the iPad but rather to the iPhone 4 hardware and OS...)
In fact, the iPad and iPhone 4 are very similar in hardware as well. The most significant difference is in RAM, where the iPhone has twice as much as the iPad.
Mentioning his or her experience on the iPad is completely valid.
That said, of course faster javascript is a benefit. Shaving even fractions of a second off web operations has huge benefits for users and results in much higher usage and happier customers.
When the performance bumps are imperceptible, it will be time to make a distinction. But on mobile devices that's still quite a ways out.
Its likely that the experience will be faster on the iPad when iOS 4 comes out for it in October.