Desk research against primary sources. Figures are traced to the issuing UAE authority and linked on the page.
The honest way to choose is to work backwards from what you will actually be doing most days, not from a ranked list: a trip built around the beach and nightlife points to Marina or JBR, one built around sightseeing points to Downtown, and a trip on a tight budget with an interest in heritage points to Bur Dubai over either. Business Bay and Palm Jumeirah suit narrower briefs — central value, or resort seclusion — and are worth it only if that specific brief matches your trip.
The metro check in the common mistake is really a proxy for a bigger question: how much of each day you lose to transfers between where you sleep and where you spend your time. A slightly pricier hotel within walking distance of a metro station or your main activity usually beats a cheaper one that adds a taxi ride to every plan, once you count the time as well as the fare.