I've never had any problem with any of my multiple chargers either. But a further comment ...
It appears that the Nexus will charge, if current is available, at up to about 1.2A. It appears that it draws about 0.5 or 0.6A to run. Thus the 2A Asus charger will run it and charge at full rate simultaneously.
When "off", the charge rates from my Motorola 850mA changers and my Asus 2A charger seem substantially the same. When "on", charge is quick with the Asus charger, and slower with the Motorola. I have a car charger that is 500mA max, as are most computer USB ports (that's the USB standard). Depending on screen brightness and what I'm doing, the charger sometimes doesn't even keep up ... but it is close.
If I plug it in going to bed, all seem to fully charge it by morning.