If you're still struggling to decide which carrier to use for your iPhone 5, you may have had some of the decision made for you. Following statements by Verizon that hinted simultaneous voice and data still wouldn't be an option despite the inclusion of LTE, which theoretically frees up CDMA for calls, we've confirmed with Apple spokesperson Natalie Harrison that this is indeed the case. It's "not yet possible" to do side-by-side CDMA voice and LTE data on a "single-radio" design like the iPhone 5, she says. That's technically true, although it may be a case of Apple wanting to keep hardware differences to a minimum between CDMA and GSM users.
AnandTech founder Anand Lal Shimpi tells the New York Times that Verizon phones like the Galaxy S III, which don't have this limit, follow a different approach: where Apple uses a second antenna to improve overall reception for a single connection, Samsung and other phone makers use theirs to keep both data and voice flowing in harmony. While it's a tradeoff with its own benefits, the choice means that iPhone 5 units for Verizon, Sprint, and every other CDMA carrier still won't let you check your e-mail in mid-call without WiFi. If that's an issue, you'll have to turn to AT&T (or T-Mobile with an unlocked phone) to get your fix.
http://www.engadget.com/2012/09/13/...ltaneous-voice-and-lte-data-on-cdma/#comments
Well, Seems like the Iphone5 for Verizon/sprint/other CDMA providers will not have simultaneous Data+voice
The GS3 has it. The more I look at this, the more I see why Apple tried hard to get the GS3 banned.