Clever characters can use the 5 min rest rule to their advantage by actually retreating once in a while. Something that never ever happened in my 3e group.
For instance, let us say you have a party fighting some hobgoblins in a forest. On higher levels they could just use blast of frost or similar immobilizing spells, while on lower levels they could use... some strategy like going up a ravine or something where the hobgoblins have to go around to get to where the PC's are. (They don't want to go up the ravine because of the large boulder at the top of the ravine, now will they).
That way a party could get to use their encounter powers twice against the same set of enemies. Something that should change combat quite a lot. In 3e you were generally at max efficiency in round 2+ because you couldn't get your buffs up faster than that. And then in round 3 or 4 the fight would be over