It appears that AT&T will still have an edge on rival carriers when it comes to one key iPhone 5 feature.
The models for both Verizon and Sprint won't let you do other data-hungry tasks while making a phone call on 4G LTE networks. When you're making a voice call on either of the two networks, you'll need to be on Wi-Fi if you want to pull data inside apps, including the Safari Web browser.
"The iPhone 5 was designed to allow customers to place a voice call on the Verizon Wireless network, while simultaneously allowing customers access to the Internet over the Wi-Fi," Verizon said in a statement to CNET.
"The simultaneous voice and data capability on LTE does not apply to the iPhone," Sprint told us.
AT&T meanwhile touted the feature, which it's had an edge on against competitors since Verizon picked up the phone in 2011.
"AT&T customers have the ability to talk and surf simultaneously on the iPhone 5," the company said.
The issue stems from the iPhone 5's lack of a third antenna, according to the New York Times. Apparently those devices that do support calls and data on Sprint and Verizon have an extra antenna that is able to pull data from the 4G LTE network while the original antenna handles the voice.The difference between the devices was not mentioned by Apple yesterday during its unveiling of the new iPhone, which goes up for preorder just after midnight Pacific tonight and hits store shelves on September 21. That information is likely important to those who might be considering which network provider to choose given the addition of 4G LTE.
The shortcoming is not endemic to the networks on either carrier. 4G LTE smartphones offered by both providers support simultaneous voice and data when on the higher speed, including Samsung's Galaxy Nexus 4G on Sprint, and the more recent Motorola Droid Razr M on Verizon.
CNET's Kent German contributed to this report.