I agree about the logic chess. The game tells you what to look for, and yet the number of "I'm not sure what to do here" moments are still pretty high for me.
Also, I suspect that part of the difficulty debuff stems from how easy it could be for a casual player to walk in and realize they have no idea what's going on. If you're picking the game up for the first time in a couple of months, you're -probably- not going to remember the first half of Case 3 in any coherent way.