No, I'm not talking about the Amber diceless RPG or a LARP... I'm talking about something I like for 4e that I feel like some critics ignore.
I've found that, aside from some condition and movement look-ups, we can set aside our PHB, DMG, and even MM most of the time in 4e. With power cards, or power sheets, or power-whatevers filled out by the players, and nice concise monster stat blocks included in published adventures, there is a lot of time saved [for me] to run back and look up rules.
The horizontal format DM Screen has a lot of condition and action info summarized there, and that helps a ton. Sure, the errata are not in my PHB because I don't have the super-deluxe version yet, but I don't miss them yet either.
All in all, this time saving helps me feel the game is easier to run, and once a player becomes familiar with their own specific character--what that character can do, as opposed to the whole darn game system--play is faster. I've run 4e sessions with 4 - 6 combat encounters plus roleplay, in one night, which I never ever did in previous editions... and they were not rushed, they were fun!