So with not much difference as far as looks and form factor is concerned, lets take a look at what has changed. I’ll start out by focusing on the three areas that I think are the biggest improvements on the iPhone 4S

New Hardware

The iPhone 4S is equipped with the latest Apple Dual Core A5 chip which is the same chip found on the iPad. This makes the new iPhone 4S fast. Incredibly fast. While the iPhone 4 is no slouch when it comes to performance, you could still feel the stutter and lag when moving between applications. Not much so on the 4S where everything is just butter smooth. The touch response is probably the best I’ve experienced on a Smartphone and applications also load faster on the 4S. The following screenshot shows the score of SunSpider on the iPhone 4S.

That score of 2200 is pretty much as fast as any other Smartphone we have tested and almost 1200 points lower than the iPhone 4′s score of 3400.

Better Camera

I’m not as trigger friendly as some other people I know when it comes to using the camera on your Samrtphone. Yet, with the iPhone 4S, I took over 500 pictures within a week. Granted, this was mainly because I was on vacation with the family, but even on vacations, I don’t think I’ve even taken even half as many pictures from any other Smartphone. Yes, the camera on the iPhone 4S is incredibly good and more importantly, very fast.

With iOS 5, you can launch the camera from the lock screen and use the Volume+ button to take a picture. I found launching the camera and snapping a picture on the iPhone 4S to be faster than Samsung’s latest MV800 Point’n’Shoot camera that I was also carrying with me during vacation. Granted, the P&S performs better under lower-lit conditions and has an optical zoom, but the convenience of carrying and snapping from the iPhone 4S won.

One funny thing I found is that the built-in picture viewer of Windows 7 shows pictures I take from the 4S upside down, however Picasa shows them correctly and from I’ve read, it’s actually Windows that’s at fault. The iPhone 4S also does 1080p video recording which I also found to be of pretty amazing quality.

Siri

No discussion of the iPhone 4S would be complete without mentioning Siri which is finally taking the voice based usage model mainstream. Yes, there have been solutions before but none has really managed to pick up. My experience with Siri proved to be a mixed bag- something I was expecting for a very valid reason.

Using Siri to check the weather or set an alarm was a no-brainer. It would work almost every single time and didn’t require me to use a robotic tone that you’d expect of a voice based system. I could simply say “Wake me up at 7” or “Will it rain tomorrow” or even “Remind me to pay bills tomorrow” without any effort. Even slightly complex sentences like “Set up a meeting with Rabeeh for 4PM tomorrow” worked, although Rabeeh was replaced with “Chubby” and that is where Siri falters.

Using western names like John or Paul work fine but trying to call or text people with names like Taimoor or Rabeeh almost always never worked. I’m not sure if Siri will get trained over time to learn these names, especially since there is no manual correction or training- for example, I couldn’t define Rabeeh from my phone book when Siri couldn’t understand who I was trying to contact. That will significantly cut-down the usage of Siri in this part of the world. Also worth noting is that you need a data connection for Siri to work so if you don’t have 3G or are not connected to a Wi-Fi, it just wont work.