In her post, Mika Epstein (@Ipstenu) wrote about the process of porting some CMB code to CMB2. I especially appreciate the last paragraph:
Simply put, CMB2 does it well, obviously, and simply. The code is easy to understand and implement. I wish it was in core. It’s around 3 megs, but 2 of them are from translations, so it’s really not as horrible as all that.
Thanks Mika! — http://halfelf.org/2016/migrating-cmb-cmb2/