This is a good summary but a couple points that I would add: Explorer is better for foreign currency spending ($4 = 1 mile) and also has its own bonus categories ($3 = 1 mile) though not as lucrative as EveryMiles but it includes any airline and some selected merchants.

A differentiator between the two would be the transfer partners. EveryMile offers hotel partners and some more unique airline partners (e.g. it’s the first card in HK to partner with Air Canada AFAIK) but Explorer includes Virgin Atlantic and some others that may be a draw for some people.