nospam wrote
Danny D. wrote
Rod Speed wrote

Too much voltage will destroy things.

And does when the electronics in the
socket fails and delivers full mains
voltage to the device plugged into USB.

But that can happen with ANY USB charger.

theoretically yes, but quality chargers have
protection so that it is highly unlikely to happen.

Impossible, actually.

cheap chargers skimp on the protection

Or don't have any protection at all.

and everything works out ok.

Presumably you left out a 'hope' after the and.

often it does but sometimes it doesn't.

in other words, don't buy noname crap.

It aint just the name that matters.

To be more specific on the question, since the spec on two ipads
would be to source about 2.1 Amps x 2 which is 4.2 Amps of current
(aka 21 Watts) of power, is there a MORE POWERFUL dual-USB wall
outlet receptacle than the best one I found, so far?

http://www.enerlites.com/61501-tr2usb.html

there is no point for more power, as nothing will sink it.

Wrong, as always.

for wall outlets with usb ports, the thing to look for is if the usb
ports are always on or if it can detect if there's a device plugged
into it and if not, disable the usb port and not waste electricity.

There is no wasted electricity with a proper switch mode design.

You only get that effect with transformer based systems.