On paper at least I think Enlighten is the smarter idea than Lightmass. Having movable, color-changing or on/off lighting with real time GI in combination with baked lighting has a lot more use cases than completely baked with no dynamic GI at all. I often read Enlighten works only for static objects. So what? Lightmass is entirely static to begin with.
Of course then you factor in the price which is 0$ for lightmass and 125k$ for Enlighten, things start to look different.