Do I want a 4S or is there any major differences?
The iPhone 4S and iPhone 4 models all use the same general all stainless steel body design and a thin “metal band” that wraps around the sides of each phone. However, the iPhone 4S and iPhone 4 (GSM) have an access panel on the right side (and an enclosed Micro SIM card) and the iPhone 4 (CDMA) does not have an access panel or a SIM card.
Additionally, the iPhone 4 (GSM) has three antenna “breaks” in the metal band (one on the top and one on each side toward the bottom) and the iPhone 4 (CDMA) and iPhone 4S have four (two on both sides toward the top and bottom).
The rear camera also has considerably better specs on the iPhone 4S — capable of shooting 8 megapixel stills and 1080p 30 FPS video. The iPhone 4 models, by contrast, are capable of shooting 5 megapixel still photos and 720p 30 FPS video. Both lines have a VGA quality front-facing camera designed for use with Apple’s “FaceTime” software (although it works equally well with third-party applications like Skype). The camera in the iPhone 4S is faster, too, and is ready to take photos within a second of launch and additional photos within a half second.
The model number printed on the back of the GSM-equipped iPhone 4 is A1332, the model number on the back of the CDMA-equipped iPhone 4 is A1349, and the model number on the back of the iPhone 4S is A1387.
If the iPhone will boot, it may be even easier to lookup any of these models by order number with Everyi.com’s Ultimate iLookup feature or the EveryMac app. Apple refers to the order number as “Model” in software. To find the “Model” select the “Settings” app and then click General > About > and scroll down until the field is visible.
Battery Life Differences
Battery life has changed a bit between the iPhone 4S and the previous iPhone 4 models. All of these models provide an Apple estimated 40 hours of audio playback, 10 hours of video playback and 6 hours of Internet use on 3G, but Apple has increased the official battery life estimates for the iPhone 4S to 8 hours of talk time on 3G (up from 7 hours on the iPhone 4 models) and reduced the official Internet use on wi-fi (9 hours down from 10 hours). Standby time also has been reduced from 300 hours to 200.
In “real world” testing, these differences are muted for most tasks, but the difference in battery life during 3D gaming use is the downside to the significantly improved performance of the iPhone 4S for graphics tasks.
Wireless Connectivity & Data Differences
A major point of differentiation is that the iPhone 4S is a dual-antenna equipped “world phone” that supports both GSM and CDMA networks — UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz), and CDMA EV-DO Rev. A (800, 1900 MHz) — and the “antenna automatically switches between send and receive.” It supports 802.11b/g/n and Bluetooth 4.0, too. HSDPA is up to a theoretical maximum of 14.4 Mbps.
By contrast, the earlier iPhone 4 models support either GSM or CDMA networks, Bluetooth 2.1+EDR, and only support a maximum theoretical HSDPA download speed of 7.2 Mbps.
Unfortunately, it also is worth noting that Apple has disabled the CDMA capability on unlocked iPhone 4S models purchased in the United States.