I agree.
I tested my cell phone and charger, about 3 cell phones ago, with a 12V 140W 'Freedom Jazz' inverter(?).
The Wall Wart was the 'old' transformer type.
From memory, Grain of Salt,
The inverter used 100ma just being On. Not 99 or 101, but 100, which I found strange.
Seems like-
The inverter and unloaded wall wart pulled 110ma.
The inverter, wall wart, and fully charged phone (with it's light on saying 'charge complete') pulled 115 or 120ma.
The inverter, wall wart, and 2/3rds dead phone pulled a few hundred ma, which quickly ramped down to the 250ma range, and decreased with time.
Going with the 10:1 / 120V:12V idea, and the wall wart adding 10ma at 12V, or 1ma at 120V.
The transformer wall warts get a lot warmer with MSW, leading to they waste more power on MSW than true SW. Leading to they don't waste all that much plugged into the wall.
Remember this was the old inefficient transformer wall wart.
The new ones are all much more efficient switchers (electronics are cheaper than copper).
Probably have to test a few switchers, grid fed or TSW, with an AC mA meter.
Crap. Now I have to do it, but later. I will post results if you are interested.
G-