With Android appearing in more and more places it will become harder for it to universally meet all detailed design questions.
Font styling and typography go well over my head, but we all notice when things are not quite right, even if we can't explain why. Someone has to pay attention to the fine detail...
The easiest way to identify the new version is to look for the R and K. They were some of the rowdier glyphs from version one and have been completely redrawn. Also check for the dots on the letter i or in the punctuation. We have rounded them out to make the types a little more friendly when you look at them closely. We also rounded out the sides of the upper case characters like O and C which makes the font feel less condensed even though it still has a high character count per line.
We see Roboto as an evolving type family and plan to continue to change and update it as the system evolves. It used to be that a type family was designed once and then used without change for many years...The old model for releasing metal typefaces doesn't make sense for an operating system that is constantly improving. As the system evolves over time, the type should evolve along with it.