There’s little doubt that Apple’s iPhone has forced a revolution in the mobile industry, with the last three years having largely been defined by companies trying to come up with an “iPhone killer.” However, a number of iPhone users who love their devices have been less-than-thrilled with wireless service from AT&T—and a new survey from professional services firm Deloitte finds that nearly half would be “very interested” in dumping AT&T in favor of Verizon Wireless.

AT&T has had an exclusive deal to offering the iPhone to U.S. consumers since its debut in 2007, and a number of iPhone users have consistently complained of poor voice and data service from the company. Even Apple itself has expressed frustration with AT&T, such as when AT&T significantly lagged international carriers in offering MMS and tethering capabilities for iPhones. Apple has entered into multi-carrier agreements in several international markets, which has led to seemingly endless speculation that Apple may bring the iPhone to Verizon Wireless—the largest mobile carrier in the United States—in the near future. An iPhone on Verizon’s network would have to be a new model, since Verizon’s CDMA technology is incompatible with the GSM technology used in current iPhones.

At a Goldman Sachs investors conference, AT&T CEO Randall Stephenson downplayed the potential impact of losing iPhone exclusivity, claiming that roughly 80 percent of AT&T’s iPhone users either received their devices through their business or were on family plans, making them unlikely to switch to another carrier.

The Deloitte survey also found that some 41 percent of respondents use a smartphone as a replacement for a notebook computer or mobile device while away from home, and that nearly a third of younger respondents—ages 14 to 27—were playing fewer games on devices like game consoles because they were playing smartphone games instead. The survey also found that 55 percent of respondents weren’t very interested in purchasing Apple’s iPad tablet computing device.

The survey of 2,000 U.S. consumers between the ages of 14 and 75 was conducted in late June and early July.