One of the strong points they mentioned, was to have PlayTesters testing the game and new features
during development.
The Developers where not allowed to interact with the Testers, and only set up the game, and monitor
their Problems.

This of course is the most objective method to value new features, and resolve
personal opinions within the development.
But its also quite costly.

They also emphasized the need to concentrate on features, that actually enhance the gameplay,
and take the methods, that where enhanching the game, while beeing quick to develop.
(so no time is wasted on complex features that result in no better game)