1. It’s the Same Phone
2. Verizon Network Is Slower
While Verizon's 3G network coverage is more expansive and reliable, AT&T still has the edge on speed. In fact, in some areas AT&T has a huge lead on data speeds. For the average customer the difference may not be a big deal, but if data speed is essential to you, the AT&T iPhone will still outperform the Verizon iPhone.
3. No Data and Voice at the Same Time
As noted in the smug AT&T commercials of last year, Verizon phones can't talk and surf the Web at the same time. The Verizon iPhone is no exception. We don't actually know many people who absolutely need that function, but if you do, stick with AT&T.
4. No SIM Card
This particular detail only applies to people who are making the switch from another carrier (coming from AT&T or T-Mobile). Verizon's CDMA network doesn't use SIM cards, so changing phones isn't as easy as just plugging your SIM card into a new device. While the transition still isn't that daunting, having no SIM card is certainly less convenient, especially when traveling abroad.
5. The iPhone 5 Isn't Far Away
And finally, the most compelling reason not to get a Verizon iPhone is also the same reason not to buy any iPhone: A new version of the iPhone is likely coming soon. The iPhone 4 (the latest version available on AT&T and Verizon) was announced last summer and industry experts agree Apple is likely to announce the iPhone 5 this summer. That means the Verizon iPhone will become obsolete in just a few short months. Now that Verizon has a partnership with Apple, it's likely that the company will be able to offer the iPhone 5 at the same time as AT&T. If you want the best iPhone, then you're better off waiting.