obvious statement but- instrument flying is an extremely perishable skill, and as such has to be practised regularly. Instrument appreciation is just that ,an insight, nothing more.
I would suggest that the 'worst' part is the initial whiteout when you enter cloud,and its how you deal with it ,that matters because if you get that bit wrong then the rest is irrelavant.
Herein lies the problem as to go from happily flying along to into cloud straight onto instruments is very difficult if you are not practiced at it, and particularly in a small unstabilised aircraft.
The instrument appreciation whilst useful cannot prepare you for inadvertant IMC - and it should always be stressed that the best way of dealing with it is to make sure you dont get into it in the first place!Increasing the amount of IF flying for the grant of a PPl will not achieve much, except increasing the cost.