However, Apple included a footnote in its press release noting that "HSDPA availability and network speeds are dependent on carrier networks."

In fact, only AT&T will support HSDPA. On Sprint and Verizon networks, download performance is governed by the CDMA/1x EV-DO rev. A standard -- so speeds will reach up to 3Mbps at best, according to industry standards.

Additionally, AT&T will only have the faster 14.4Mbps downloads where it has provisioned HSDPA. And that download speed is considered a theoretical maximum; in reality, the average user in a crowded cell tower zone won't experience that level of performance.

Gartenberg said the network improvements are not what he considers the best new features in the iPhone 4S. Instead, he pointed to the faster dual-core A5 processor, the 8-megapixel enhanced camera and speech recognition capability using Siri.

The fact that Apple stuck with the same exterior design as the iPhone 4 isn't going to be a problem, he contended. "People like that design and it sold incredibly well," Gartenberg said. "It makes sense to keep it."