High Capacity Phone Batteries - are they for real or a scam?
You are correct. The true measure of a battery's capacity is Wh. As you noted, the information on the new battery is contradictory. Either the Ah is wrong and it is higher capacity or the Wh is wrong and it is the same capacity.

The easiest way to tell is to try the new battery. 25% increase in capacity should be pretty easy to tell over a few days.