Well, they have included the spell level cap (maximum available spell level minus metamagic modifier), which is good, as it does only allow to cast metamagic spells you normally could, anyways.
Therefore I don't see anything inherently wrong with this, other than taking further away from the spontaneous casters (I don't think metamagic is meant to be balanced all by itself, but rather part of the whole balance between the classes and an additional equalizer for their extreme lack of diversity - even with that discrepance in the use of metamagic, most people consider the prepared casters to be "better").
It generally makes metamagic a viable option for prepared casters again, which is good.
But I'd probably consider to remove (at least partially, like adding one or two levels to the cap) the above-mentioned cap for spontaneous casters, if using that variant, to retain the class balance. More power for lack of diversity sounds like a fair trade to me.
Bye
Thanee