SE isn't going to do this because it will take longer time to develop but dungeons should have multiple paths and multiple objectives.

paths that have more trash mobs for AOE pulls.
paths that have big trash mobs where AOE pulls don't make sense (like 3x malboros).
paths that have an extra mini-boss.

players are going to flip out in DF because people will want to go different ways.

puzzles are not a good idea unless it's single player stuff like what happen at the end of the 3.1 MSQ. those should be longer and you should be able to replay those for like 1/3 the tomes of a normal dungeon daily.