I found I flew better in-cloud than by using a Hood as my instrument scan and other tasks got much easier due to the ability to use my peripheral vision.
I fully agree that the best learning is done doing it for real.....with a proper Simulato being the second best option.
The Simulator is where the best learning takes place but for straight forward flying ability and confidence boosting....flying in real weather is the best course.
One observation about pilots and instrument flying.....are they flying "instruments" or flying the Attitude Indicator?
My Army Instrument Instructor , regardless of policy, insisted the AI was a secondary instrument that was used to set a new attitude to cause some effect that was determined by what all of the other Instruments were indicating.
The way I used to check for this in the Sim or the aircraft was to begin the age old "Unusual Attitude" drill...with the Student putting his head down and closing his eyes....while I moved the aircraft about all three axis.....but at the start of it while straight and level I would adjust his attitude indicator 5-10 degrees wing low.
Then...when in an all but wings level attitude (5-10 degrees of bank) showing on his attitude indicator....off we went for the roller coaster ride.
Remember....there were three Attitude Indicators in the aircraft that he could look at any time he wished.
Most would take three evolutions of going wings level...then correcting a turn...then correcting a turn...then correcting a turn.....before realizing something was wrong with his Attitude Indicator.
Sadly....some would never figure it out and thus never be in full control of the aircraft either physically or mentally.
That Instructor is the one that required me to fly a Huey...no SAS, with no Gyro's, fixed card heading indicator, and mag compass then complete an NDB Hold and NDB approach....before he would sign me off.
Are we seeing that level of training these days?
Mind you those skills are highly perishable
We should also remember another Aviation Law... "Never let bad judgement put you into a situation where you need your best skills!".