AT&T's public relations team proudly Tweets the fact that a new PC World study of wireless carriers shows a marked improvement in AT&T network performance. According to PC World, their testing methodology (they got help from Novarum) involved 51,000 separate tests covering 850 square miles of wireless cell coverage in thirteen cities. Their conclusion? AT&T's network speeds have jumped 84% in eight months, with download speeds now 67% faster than AT&T's competitors. The study also found that AT&T reliability and performance in their trouble markets of New York and San Francisco has significantly improved:Guess what consumers? Loud complaining helps, regardless of what some will say. Other interesting tidbits from the study include the fact that Verizon Wireless' average download speeds have dropped 8% since PC World's last study. The report's numbers indicate that Verizon may be struggling to keep up with smartphone user bandwidth demand, while Sprint is not (though Sprint's nasty habit of continually losing customers may be helping there). The report appears to really hammer the Motorola Droid performance on Verizon's EVDO network in terms of both speed and reliability:So is Verizon going to be 2010's wireless capacity whipping boy? Probably not. As we've noted, the carrier's planning to launch faster LTE service in 25 to 30 markets this year, and plans to have the entire network upgraded by the end of 2014. Like AT&T, Verizon has plenty of cash to keep ahead of demand when they actually set their mind to it; Verizon data service revenues grew from $12 billion in 2008 to $16 billion in 2009, and their new wireless data pricing certainly won't leave the company's upgrade budget standing in any soup lines in 2010.