High end wings, ie. not for beginners have proven to be more efficient. It was previously known that a paraglider is always more efficient than a paramotor wing because it was designed to lift more than fly forwards. PPG wing is more about forward speed and less about lift. Lately though wing like the Ozone Viper 4 and Freeride have been showing me how efficient a paramotor wing can be.
I have been flying since about 2004 on various wings. From days of flying 31m paragliders, to 29m reflex paramotor wings. Now days I mainly fly a 19m uncertified motor wing. It is one of the more efficient wings I have flown.
Point is, size and type of wing is not the only factor, modern design is having a bigger impact on efficiency.
How do we make a list and quantify wing efficiency?
On my 2 stroke paramotor, I recognise efficiency by litre per hour burnt of fuel and also distance covered with speed. Do you want to just stay up as long as possible or get somewhere?
The differences are not small, I have wing which burn 5 litres per hour and another that burns 2 litres per hour. I can tell pretty quickly by the rpm at level flight.
I guess when it comes to electric, I will be able to tell by current draw at level flight. Wing choice can make a difference of 20 minutes or 40 minutes flying.