MIAMI (CBS4)-South Floridians will have the fastest downloads if they go with Verizon, but will have the most reliable data transfers with AT&T, according to wireless carrier rankings by RootMetrics.

Washington-based RootMetrics, which measures mobile carrier performance, released it’s first test results for the greater Miami area this week, according to CBS4 news partner The Miami Herald. It gave Verizon the best ranking for Miami, primarily for its 4G LTE network connection speeds, which were found to be four times as fast as T-Mobile’s HSPA+ 4G, and almost seven times faster than Sprint’s WiMAX 4G.

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For call performance, Sprint customers were three times more likely to drop a call than with the other three major carriers.

Every carrier but AT&T scored poorly in a performance test for sending and receiving data. The report said T-Mobile had a data failure of 18 percent, followed by Sprint failing at 17 percent and Verizon at 9 percent. AT&T had a two percent failure rate.

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The fastest text messages were sent on the AT&T and T-Mobile networks, both taking less than 30 seconds to deliver. Sprint and Verizon both took more than 30 seconds.

The test results were based on information gathered from thousands of calls, texts and data transfers over seven days in April. RootMetrics also collects data from anyone who wants to assist in tests using the RootMetrics Cell Phone Coverage Map app, available through the Apple and Android app stores.

Miami is the third metro area the firm tested, following Seattle and Dallas earlier this year.

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