How about both, a minimum amount of good training. Sure there's always the temptation to just make the minimums, and do it in the easiest way possible. But surely training with good scenarios, focusing on the most important and/or hardest to master items shouldn't cost any more than poor training. You tie up the sims the same amount of time in either case. I'd guess maybe preparing the scenarios and "lesson plans", would take a bit more effort than just cranking out hours of lessons.
It just never occurred to me that TIME in the simulator wouldn't be put to the best possible use, FAA time mandates or not.
The results are the proof. Human-factors training and a dynamic ISD are more effective than time mandates, and airlines have the data to PROVE it. Every airline that has abandoned the time approach has actually improved their training, and in many cases increased the time, but not by mandate, but because THEIR data supported it. Some parts of the FAA actually think the airlines train only for the least expensive option. This laughable considering the ENORMOUS sums spent every year in training. The major airlines are more safety minded than many in the FAA.