This thread was started in 2011, the M stem and M handlebar have changed since then, the current M stem is higher and the current M handlebar is lower (the total height stem+handlebar is about the same).

Putting a S handlebar (or any flat handlebar) on the current M stem (as on the Explore) will result in a higher position than with the old M stem. Cables length reduction will be less than what it was with the old M stem.