The only genuine measurement of how well you insulated your home...

The only genuine measurement of how well you insulated your home is to check your electricity consumption daily.

I am doing it and found out that LCD TV, Freezers and Fridge are the largest power users, followed by pool pump ad air conditioning.

Actually, air conditioning is very energy efficient, it uses less than a freezer.

Therefore I do know that roof insulation (silver foil, rated at 3.5R) made little difference to power consumption, but the house was cooler.

The real bonus came with having windows insulated with solar guard foil (applied on the OUTSIDE) of the window. No air conditioning is needed below 37/38 C and the power consumption has significantly decreased.

My power consumption has decreased by 28%.