Y-boards don't spin faster, they react faster. The programmed delay is eliminated from the software in the new boards. Also, as Benfrain said, they have a switch, so it is easier to tell whether or not it is on.
If you want faster spin, Raven/Java makes a 9.6 volt rechargeable battery for something like $14. Put two of these in and watch it go! Warning: your motor won't last as long.