Resource leveling in a project..a useful task or a pain in the ass

The past few days have been extremely frustrating as I am trying to fix and plan my resources in a 400+ task with numerous swim wires connecting them. Managing resources in MS project is not a simple task. You can put in the names but when it comes to leveling them to the respective capacities, you have to go through a lot of pain and trust me the tool which MS project provides for auto leveling messes up the project big time..so should we put effort in leveling resources in detail? considering most project plans are never followed as they are made. What I believe is that we should do resource leveling!! but not in depth to the lowest detail. A more high level for the core team should be good enough so that the PM is aware of the challenges he/she might face in executing the phases. The rest should be left when the task is about to be started. Its as simple as following the thumb rule..." don't cross the bridge until you have reached it..but do figure out where the bridges are"