As a new player in a game of Mutant City Blues, it has struck me that the GM has a very large workload when prepping the investigation scenes if there is to be any real interaction with that scene for purposes of discovery by the players. In a group that really wants to have the rewards of personally shaping how an investigation plays out, preparation time for the GM is immense and does not end before the scene starts, it continues and expands as the players take their queries in unexpected directions, all of which demand satisfaction due to the level of expertise each character possesses as an investigator.
Obviously, a GM could simply narrate the scene and build up to skill spends and the transition to scenes where the players are expected to act with their newfound information, but that diminishes the time players can spend in that investigative capacity and forces them to focus on their deductive abilities.
What works to reduce the amount of preparation for the GM while providing opportunities for the players to explore and investigate a crime scene or mystery?