Start with where you can legally ride, then the battery, then the price you can actually verify.
Class before watts
A bigger motor does not help if the path you use bans that class. WattRank leaves class blank when the brand page does not print one.
Many US states use the three-class system: Class 1 is pedal assist to 20 mph, Class 2 adds a throttle and still cuts the motor at 20 mph, and Class 3 is pedal assist to 28 mph (a throttle, if the bike has one, is often limited to 20 mph). Cities, campuses, and trails can be stricter than the state, and a few places write their own rules instead of using the three classes. A 750 watt motor is the usual ceiling in that framework, but it is not a national license. This is general information, not legal advice. Check the rules where you will ride before you buy.
Ask for watt-hours
Range claims are marketing. Watt-hours are the size of the tank. If a brand prints amp-hours and hides watt-hours, WattRank withholds the value score instead of inventing a voltage.
A folding benchmark
The Lectric XP4 is in the catalog with a 500 Wh battery and a snapshot price from Lectric's own page.
LectricXP4Value 65from $999SampleWhat WattRank will not do
It will not fill a blank spec to make a table look complete, and it will not mark a snapshot price as live.