"IF" you understand electrical circuitry then electrically speaking there is no difference. Only by following the path do you reach the correct conclusion and the end. The hard part of cold side is the refrigerant cycle. I don't understand why there would be any difference "electrically speaking". Electricity doesn't care what the temperature is.
No there's not any question, hot side has become come a lot more technical related with controllers and combis coming into the market, whereas most refrigeration, in the food business, has stayed relatively the same.