I've read a lot of Tizen code, and EFL is by far one of the more professional and well-engineered components. And this is realizing that in relation to many open-source libs EFL is rather a goofy oddball.

95% of Tizen is a huge hairball of needless nested and overlapping indirections (custom IPC layers, serialization formats, "management" daemons, libraries to interface with them, etc.) implemented in varying (except for the pervasive messiness and broken english) C styles; deep beneath all this you have the open-source libraries doing the actual useful work. You could try to make some similar claims about Android, but the percentage would be much lower and the code quality is much higher. I wish I had some real metric to point at (maybe this article suffices?) but the code in Tizen is truly awful.

Also they don't give a shit about their bug tracker; I've had system-breaking bugs, with patches, in "new" status for over a year. Because I don't work at Samsung, I can't contribute.