Sounds very normal on the re-do
As I said earlier... slightly re-written----- Very few people bother to clean the plug, also the socket can tarnish as well.. Quality sockets self clean when you plug in and may self clean the plug as well but not all are quality.. Spring tension (in the outlet) gets weak as well.. The result is poor contact and high heat and melted plugs.
You now have a new plug, a new outlet, and clean contacts.. Naturally they work better.
A Kill-a-watt meter (About 20 bucks) is a plug in most every thing meter
Volts and frequency for system.. And for things you plug into the KAW you get Amps, Volt-Amps, Watts, Power factor, KWH and I think one or two other thigns.
I highly recommend them,, that's about a thousand dollars worth of meters, for under 20 bucks.