Actually... in the case of easy debian it isn't handling the hardware.. Maemo is - and it's optimized for it.
Whereas with Mer.. debian is handling the hardware and is *not* optimized for it.
Thus, you're going to get better battery life from easy debian than with Mer. Some things may even be faster... especially if you run the software through Maemo's interface and not have the full blown LXDE running atop Maemo.