Yeah I know, being an official flavor comes with a price tag as long as Ubuntu can't handle the changes in Gnome because of the Unity-shell they use.
The developers call it stability and polish but it's nothing more than bending and tweaking the Gnome components to fit the needs of the Unity-shell.
This has nothing to do with actual development or progress. most development in Ubuntu lies in the Unity-shell and all it's fancy ( commercial ) lenses.
I personally think this adaption process is a waste of good developer resources. But that's the price Ubuntu has to pay to be in control, but I don't think it's fair to pass this price tag to Ubuntu-GNOME too.
Well maybe this dilemma will resolve itself when the Unity-shell is ported to QT and Mir ? I can only hope