But more important to many would-be buyers, however, may be that it comes with unique technology that switches a radio signal between its two exterior antennas to provide better reception.
Those two antennas were behind the that erupted last year after the iPhone 4 launched and users found that holding the device a certain way led to dropped calls. With the iPhone 4S, Apple seems to have come up with an internal fix for the "death grip" issue, analysts said.
Apple officials only briefly mentioned the new antenna design in their presentation, and an Apple statement about the new phone, which goes on sale Oct. 14, was succinct: "Improving on the innovative stainless steel external, dual-antenna design of iPhone 4, iPhone 4S is the first phone to intelligently switch between two antennas to send and receive."
Apple didn't respond to a request to more details. But Gartner analyst Michael Gartenberg said the company probably tweaked the new phone's hardware and software to eliminate reception problems that plagued some iPhone 4 devices.
"Apple didn't go into details of what they are doing, but they were clearly laying to rest early on the issues over reception seen in iPhone 4," Gartenberg said. "Since the iPhone 4S exterior design is relatively unchanged from iPhone 4, people were obviously wondering if there would be any issues with the antenna again, call it 'Antennagate' or whatever."
With the arrival of the iPhone 4S, Sprint has joined Verizon Wireless and AT&T to become the third wireless carrier to support the iPhone. Sprint has waited four years for this opportunity, and some analysts with customers in the Midwest and among lower-income users.
Ironically, Sprint didn't crow about its big win; it didn't even issue a press release calling attention to the development on Tuesday.
"We are delighted to be part of this announcement," a Sprint spokeswoman said. "We will have more details to come shortly, but for today we would like to keep the focus on these exciting new devices that will be coming to Sprint customers."
Still, the iPhone's arrival on Sprint is significant, analysts said. "The iPhone 4S is a much bigger deal for Sprint than for Apple," said Kevin Burden, an analyst at ABI Research.
Sprint will face a bit of a challenge, however, because it will sell only the iPhone 4S and it will have to charge "somewhat premium rates" for that device, said Burden. Meanwhile, AT&T will carry the iPhone 4S but it will also be able to offer the iPhone 3GS for free and the iPhone 4 for $99 (with two-year contracts in both cases). For its part, Verizon will be able to sell the iPhone 4 for $99, in addition carrying the new iPhone 4S.
In comparison, the iPhone 4S will sell for $199 for the 16GB model, $299 for the 32GB version, and $399 for new 64GB version.
The new iPhone 4S also functions as a world phone that works with both CDMA and GSM networks.
That means that customers of Sprint and Verizon, which have CDMA networks, will have to use GSM networks if they travel abroad, since GSM is widely deployed globally. And they will also be subject to roaming policies and will have to pay rates that can be quite high, analysts noted.
"The world phone is a big thing, especially for a lot of users who travel internationally," Burden said.
Both Gartenberg and Burden noted that Apple benefits from having both GSM and CDMA inside the iPhone 4S, because it can simplify future updates to one model. "You will have one phone for multiple carriers," Burden said.
Apple boasted that the iPhone 4S supports download speeds of up to 14.4Mbps with HSDPA (High Speed Download Packet Access) technology. Burden said that capability will work on many GSM networks globally, including AT&T's in the U.S.
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."