Last weekend we started a new short campaign for 4E D&D. We wanted to try out the higher levels (15th in this case) before embarking on a proper campaign (assuming we do). One of the much vaunted improvements of 4E was that it played faster at higher level and required less DM preparation.
To me, it felt and ran a lot like the lower-level games we had played. The rounds ran quickly, and although there were more of them, no-ones turn took very long and we were back around to people fairly promptly. There was some delay as people got to grip with characters and abilities which were new to them, having not played them up from 1st level. The aboleth lasher was probably the most feared monster of the day, but the party coped with the encounters without too much trouble.
In contrast to 3rd Edition, the first thing that became apparent was the lack of "buffing" spells. No mage armour, bull's strength, protection from elements, haste, hero's feast, heroism, barkskin, enlarge person, stoneskin, false life, resist energy or darkvision in sight. And I can't say I'll miss it. No long spell descriptions to look up, and no rules arguments (yet).
Next week will bring more of the campaign to life, as we get beyond a few initial hostile encounters to get things going. And the actual adventure bit was quick to prepare. I took about 20 minutes to pick out a few creatures for the encounters. Mostly kuo-toa as I quite like frog-men and haven't used those particular ones in years :)