the geek humor is gone replaced by "Joe Smo" humor. The integration of the female characters has been poor; with a poor understanding the female humor bone by male writers. The heavy reliance of the Sheldon character has all of the other characters pushed off to the side when it was the opposite in the beginning of the series showing Sheldon as a sounding board to showing society's own quirks and regimens. It has turned into a one-trick pony with below average story telling.
To quell my disappointment I've had to stop watching the show.