On touch screen devices or when a mouse with a scroll wheel is used the scroll bars are unnecessary. in such cases they are never used and just take up unnecessary space, Which is more apparent on laptops which don't have a lot of screen real estate.

I personally preferred the way the scroll bars worked in the previous versions. Thus i think it would be nice if users had the option to choose whether the scroll bars should always be visible or work the way they did in previous versions.