I'm probably totally out of my depth posting here (as a PPL with 55 hours R22) but as the discussion relates to the value of the 5 hours Instrument time I may have something to offer.
I got the feeling from all the instructors at my school that 5 hours thing was really a joke but they are/were a very professional bunch and never forced opinions.
I had been shown and had successfully (well not too badly) carried out 180's in patchy cloud but I was always able to sneak a peek at outside reference - mayble this was for confidence building.
One day one of them very calmly and carefully and with extensive 'precautions' directed me to fly into cloud at about 4000'. He was hawk like hovering over the controls as we entered very 'thick' cumulus.
Now, I have been near too and in thin cloud on a Hang Glider several times (not on purpose of course) and really thought this would be no big deal - the initial roughness at cloud base was expected but I was suprised that the helicopter moved around as much as my glider - I could not keep steady needles.
As we entered the cloud the whole world changed, the helicopter seemed to be vibrating 10 times more than usual, outside there was just blinding white, there was no view, no reference, my senses were saying we were pointing at the ground and going 200mph. The AH was tipping left slightly. Yes, I began to correct the wrong way, yet on my (fairly good PC simulator) I can fly around in cloud all day no problem.
Even when the Instructor assisted in levelling the a/c I gently pushed back at him the wrong way, we were still slowing - about 50kts now, the instructor started predicting the outcome - I remember him saying 'upside down', I'm hunched forward right over the cyclic for no good reason, my veins are sticking out of my arm just through the force I'm gripping the lever with.. no matter how much I told myself the right way to move the cyclic my senses overcame and moved it the wrong way - even just gentle small movements.
The instructor levelled us and with lots of c/heat descended into the clear. I'm all back to normal now and we are in the clear and can fly as usual (inexpertly but I hope safely).
I was totally and utterly shaken by this experience, not the physical aspects but by my inablility to even remotely cope with the situation. All the books, all the PC simulators all the advise were as nothing. I decided at that point that hundreds, possibly thousands of hours are required to adapt out the senses and apply the instruments. It worked for me as shock therapy - another 10, 50, 100 hours I feel would not be enough.