The argument over which carrier has the fastest network speed in any given location in the United States is still up for debate. Putting network speed comparisons aside, which are often not an accurate representation of speeds, you will receive in your specific area, a new app from startup SwayMarkets aims to provide a more realistic comparison.

The app, CarrierCompare, allows users to test the network speed of their current carrier against the two other major iPhone providers. CNNMoney went hands-on when the app released last month and just posted the user data it obtained that compares major iPhone carriers in multiple locations.

Analyzing user-generated data from Boston, New York, Washington, Chicago, San Francisco, and Los Angeles, these were the results:

AT&T: AT&T is on top with the highest median speed for the above cities, which makes it the fastest 3G network—as advertised. However, the report noted its also the most unreliable: “When the network gets more congested in the afternoon hours, download speeds become more of a crapshoot. Sometimes they’re excellent, but usually they’re just mediocre.”

Verizon: Verizon came in second place for all cities but New York and recorded speeds 72 percent as quick as AT&T in most cities. Although, it did mention that Verizon is more consistent:

Verizon’s network delivers a more consistent experience than AT&T’s, with speeds varying less hour by hour…Verizon also has by far the quickest network response time, meaning that Web pages begin loading faster than on any other network after a user clicks on a link. Verizon’s network starts churning in half the time it takes AT&T’s to respond, and often about a third of the time it takes Sprint’s network.

Sprint: Sprint is in last place among the three carriers, except for in New York where it slightly beat Verizon. The carrier is the most consistent, though, by offering “speeds rarely deviating more than 25% from the median.”

The carrier’s response times were also quite slow, often taking nearly three times longer than Verizon to start loading content. Sprint’s network lag was the greatest in all six cities.

According to SwayMarkets, AT&T is the clear winner when it comes to network speed, but Verizon takes the overall top spot for speed and consistency combined. Wonder what the carriers said about CarrierCompare? CNNMoney posted responses from each of them on its blog with an explanation about data was collected.