Apple iPhone 4s Review

The iPhone 4S caught many by surprise, with Apple expected to release the iPhone 5 - but instead we got an iPhone 4 with overhauled innards. The iPhone 4S is the best phone you can buy right now. That's been true of every iPhone.
The iPhone 4S comes with a faster processor, a better camera, a smarter virtual assistant and twice the storage of its predecessor -- if you don't mind paying for it. Like the iPhone 3GS did before to the 3G, the 4S bumps the iPhone 4 down to second-class status, leaving those Apple fans who must have the best aspiring to own its decidedly familiar exterior. Apple says this is the most amazing iPhone ever. Is it? Yes, of course it is, but read on to see whether it's really worth an upgrade.
External Design

iPhone 4 legacy: the iPhone 4S looks, and feels, just like an iPhone 4. Although there are minor differences that may make some smartphone cases not compatible (my Belkin transparent case is not compatible for example), both phones feel extremely similar. I don’t think that covering this aspect further will do any good (you like it, or you don’t), except for one aspect: the display size.
Hardware
Familiar is a good term for the exterior of the iPhone 4S. When the 4 was unveiled in the summer of 2010 it was a strikingly different design from anything else on the market -- glass on the front and back, exposed screws holding together a deliciously clean ring of stainless steel. It was kind of chunky and industrial, like a tastefully refinished factory loft -- a big contrast to the smooth and nondescript models that came before. The iPhone 4 was something truly new and, for the days and weeks after its release, just spotting one in the wild caused a sensation. It was so different that people wanted to touch and hold the thing, to see how it felt in the hand.
Few are going to go out of their way to touch and hold the iPhone 4S, but that's not to say it isn't very nice to grasp. The iPhone 4 felt like a finely crafted piece of machinery and there's no doubt this one walks in those very same footsteps. Compared to your average modern Android wunderphone the 4S feels small, dense and heavy, a very different sensation than the occasionally lighter but frequently more plasticky competition. The 4S does actually have slightly more heft than the 4, but only by carefully holding one in each hand can you notice the increase from 137 grams (4.83 ounces) to 140 (4.94 ounces).
Display

For those who aren’t playing with smartphones all the time like we do, you should know that the current trend is going towards larger displays of 4”, 4.3” 4.5” or even 5”. As of now, the iPhone 4S has kept the same 3.5” format than its predecessors, with the same high resolution (960×640) that is still one of the best today. However, 1280×720 pixels displays are scheduled to come out next month, so the sharpness of the the Retina display won’t be so unique anymore.
Resolution aside, the sheer size of the display can be an important factor in the level of comfort of a smartphone. It makes text and virtual keyboard keys bigger and that increases both comfort and productivity, which is why so many iPhone die-hard fans were hoping for a bigger screen. To put it simply, the “one size fits all” design policy of Apple doesn’t quite work anymore. Just like they do with laptops, Apple will eventually have to cater to the needs of their clients who want a larger display.
The A5 dual-core processor

already used in the iPad, the A5 chip finally made it into a phone. It has an excellent graphics processor (GPU) embedded in it and its two processing cores (CPU) should help speed things up, if applications support multi-threading.

The 8MP camera, and low-light sensor

Although good, the iPhone 4 was getting endangered by phones like the Galaxy S2, which could shot images that are much less noisy. It made sense that the iPhone 4S came with a better sensor, optics and software. Its Omnivision’s OV8830 sensor uses BackSide Illumination (BSI), a sensor-building technique that allows more light to reach the sensing elements. Apple has also changed the aperture (how big the hole is) from 2.8 to 2.4 (lower is better), to let more light come in.
The combination of new sensor and A5 processor allows for 1080p video with some form of digital stabilization, which helps alleviate the tiny shakes from your hand.
Software: iOS 5

The iPhone 4S also came with the iOS 5 software update (that you can also get on the iPhone 4, and select older devices). I’ll go over the biggest changes, but keep in mind that older (and cheaper) iPhones also have most of these features, with the notable exception of Siri (more on Siri later).

Web Browsing 

The web browsing itself hasn’t changed much, but with iOS 5, it is now possible to save a page to the Reading List for offline reading. Other than that, it’s pretty much the same than what we had on iOS 4.x. Normally, the web browsing experience should be a bit faster, but I couldn’t really tell in real-world usage – probably because the data download remains the main performance roadblock.
While the screen resolution makes everything very sharp, it’s so small that it’s not always readable, at least not comfortably, because letters can be so small.
Virtual Keyboard
 the virtual keyboard hasn’t changed one bit. Overall, I really like its responsiveness, but it is very small (due to the screen size), so it is in general not as comfortable to use as larger touch phones.
Battery life

This video courtesy of PhoneArena