The biggest downside to me is games. I returned an iPad Pro for the 12" MacBook. Just as portable and Civ V and Steam/Xbox streaming is a much better use of my limited gaming time than anything on the app store.
I can play almost any modern game on the darn thing, which is quite impressive.
Even The Witcher 3 will run on it, I understand (haven't tried it myself). At low settings and low res, granted.
Definitely true, and burns through battery like crazy.
But it is still impressive something that tiny can run modern games at all. And frankly it does a really good job.
There are better laptops for mobile gaming, but not in that weight and size class or even close.