Did someone say Mate? Take a sip of this:
It is installable. I have it installed. It is stable. It is fast and as regards memory usage it sends out a challenge to other so called light desktop environments. It is built upon Utopic Unicorn. It is not my beverage of choice. But there you go. Mate developers are doing this and who better to do it. There are others including at least one Canonical developer.
If you people would really like something like Ubuntu Mate to be successful, then stop wishing and join some teams. Help make Ubuntu Mate Remix an official Ubuntu Flavour.