Though Verizon(NYSE:VZ) and AT&T(NYSE:T) still have the largest and most reliable wireless networks, Sprint(NYSE:S) and T-Mobile(NASDAQ:TMUS) are catching up, according to the RootMetrics 2nd Half 2014 U.S. Mobile Network Performance Review.

As you can see from the chart below, the spread between Verizon, which had the top network, and T-Mobile, which came in last, is relatively small.  

Second half of 2014. Source: RootMetrics

These numbers are huge changes from the same report a year earlier, where Verizon was still on top but had a much lower score, and T-Mobile and Sprint were well behind where they are now. In fact, the scores for the bottom two in the second half of 2014 would have been good enough to top the charts by a reasonable margin the year before.

Second half of 2013 Source: RootMetrics

"While Verizon and AT&T top the charts, all networks are getting better. We saw improvements across the board in data speed and data reliability, which are fast becoming keys to everyday mobile experience," wrote survey author Patrick Linder. "The biggest improvement stories belong to T-Mobile and, especially, Sprint with its marked call improvement ...The upgrades from these two networks are clearly starting to take hold and are impacting performance, in particular, at the metro level. In short, performance is trending in a positive direction, and consumers are benefiting from the changes we've seen."

The bottom is getting stronger, and the difference between any of the four carriers is shrinking. Every network is markedly better than it was a year ago, and none scored poorly.

This suggests that network quality may no longer be a meaningful way to judge wireless carriers.

Can they all be the best?
Every wireless company touts the strength of its network. It is like the local pizza place that dubs its buffalo wings "world famous" or "award winning" while providing little info about the source of the global admiration or exactly what awards were won. In this case, however, RootMetrics shows that in some fashion -- at least in the wireless world -- everyone can claim the best network.

The survey ranks the networks on overall performance, network reliability, network speed, data performance, call performance, and text performance on a national, state, and metro area basis. All four major carriers had some first place finishes. Verizon still finished on top with 799 first place wins followed by AT&T at 493, T-Mobile at 205, and Sprint at 167.

Just like at an elementary school end-of-year awards assembly, everyone is a winner. Except, in this case, Verizon won in 48 out of 50 states, while victories for the other carriers came mostly at the metro level. That means any of the four carriers might be the best choice depending on where you live but not as strong should you travel.

In general, however, though Verizon and to a lesser extent, AT&T, are still clearly on top, the differences between them and Sprint and T-Mobile are relatively small.

What does this mean for consumers?
In some ways, the fact that Sprint and T-Mobile have steadily closed the gap makes them much more viable options for consumers just about everywhere. That is bad news for AT&T and Verizon, which generally charge more for their service, justifying it in part by claiming to have superior networks. 

"Sprint and T-Mobile have both invested heavily in upgrading their networks, and the payoff is starting to show," Linder wrote. "T-Mobile in particular continues to show very fast speeds in many of the metro areas we test and, as we note below, even recorded the fastest median upload speed we saw from any network in the second half of 2014."

What is challenging for consumers is that while Verizon is the clear winner, its margin of victory is relatively small. That means, for many people, the best choice for them could be any of the four, which requires either diving into the extended RootMetrics report or testing mobile networks on different devices in the areas they are likely to use them. But then again, options are never a bad thing.

Sprint and T-Mobile have largely erased what was once a significant deficit, and for most of the country, either one would be a viable option.