@Douglas-Kryder They both look 100% identical physically. From your link:
"What differs Power Dock 2 from the original Power Dock is that it has the Battery Level ADC that allows you to accurately monitor the voltage of your battery. Another update is that GPIOs 18 & 19 are now available on the Expansion Header!"
What does this mean in practical terms? Is the original dock fully compatible with all the expansions (relay, servo, oled, etc.)? will the GPS expansion work?