While the conference room was primarily set up as a consistent testing environment for PBR, and feature a higher poly count for certain models, in addition to a rain drop effect applied to the soldier's armor, I wouldn't call the GDC demo 'not even close' to being representative of the final games. The games ended up using the tech well.
Examples from the room:
Final game:
Phantom Pain - An improvement from GZ. The last two shots displaying different wetness effects as they appear in-game.
Ground Zeroes