Lon.TV has made a very interesting video where is measuring a 60 Watt USB-C Dock against the Macbook Pro 15 87 watt power adapter to see how is handling the charge part with the CPU and GPU test. In the test, a Kavalan USB Type-C Power Meter Monitor, Multimeter Charging Tester for V/A/Watts, Bi-Direction Indicator with... is used to measure the amps and watts that are used.
Also, an app is used in measuring the real-time charge for the battery while the dock and Apple charger is used, the app is Battery Health.
Lon wants to see if there is any performance impact when using a 60 Watt USB-C Dock instead of the Apple Power adapter that comes with MacBook Pro 15. Watch the video in case you are interested to see the differences and see how a USB-C Dock is doing: