Everytime I start to get excited I check my enthusiasm after reading post-game quotes. From two different people on two different teams, I've read that what the Packers defense showed was far more than what they expected normally in the preseason. Simply, as we're testing out our defensive packages and stunts, we show more of our hand and appear to be a better football team since we're playing harder.
Are we better? Yes, there's a very good chance. Are we the best team? Not yet.
I think preseason has never been indicative of team performance, rather preseason gives a good idea on how individuals have improved or regressed.