The FAA and civilian aircraft manufacturers have done many studies on emergency procedures. These studies find that pilots who try to handle emergencies using memorized procedures typically make many more mistakes than pilots that use emergency checklists and quick reference handbooks. Memorization leads to rushing which leads to mistakes. Mistakes lead to crashes. As a results, the FAA and civilian world has gone away from memorization and instead stresses a non-rushed use the checklist approach to the vast majority of emergencies and malfunctions.My counter argument would be that memorizing more EPs gives you better confidence to handle them in a real life situation and I think it enhances your ability to recognize what the EP actually is more quickly.
We have 7 memory procedures in the A330 and 2 of them are O2 masks on during a rapid/explosive decompression or an electrical fire. We memorized 3 pitch/airspeed combos for takeoff airspeed failure, wind shear escape, ground proximity escape, V1 cut and brake failure on landing. That's it. Every other emergency there is time to go to the checklists/QRH.
I know helicopters are different beasts but as a generalization this should hold for them too.