I’ve been using the iPhone 4S heavily for about 24 hours now. After finally getting the phone activated on AT&T yesterday afternoon, I’ve had a chance to use the device pretty extensively.

The iPhone 4S has three main selling points: a faster processor, better camera, and Siri. Here are my initial thoughts and impressions of Apple’s newest smartphone…

It’s Super Fast

While the iPhone 4S looks nearly identical to the iPhone 4 on the outside, Apple has tricked the 4S out on the inside. The A5 processor means super fast performance. I’ve noticed considerable speed improvements when rendering web pages in Mobile Safari, and games playback is much faster and smoother.

An excellent way to see the speed improvements Apple made in the iPhone 4S is to mirror the device with an Apple TV. After I enabled mirroring, I used my iPhone 4S as a controller to play graphic-intense games like Shawdowgun and Infinity Blade. The Apple TV’s response to my movements on the 4S screen were nearly instantaneous, and I didn’t notice any lag whatsoever.

Mirroring an iPhone 4S is also great for browsing the web and checking apps like Facebook. When compared with the iPad 2’s mirroring feature in iOS 5, the iPhone 4S actually looks better on the Apple TV than Apple’s newest tablet.

One thing I will say is that battery life on the 4S seems to be lacking. This could be because my handset hasn’t gone through a full charge cycle yet β€” I’m just not sure. I’ve also been using it pretty regularly over the past 24 hours. Apple claims that the 4S actually gives you an extra hour of talk time, so I’m going to give the 4S the benefit of the doubt for now.

The Camera is Great

Apple wasn’t kidding when it said that the 8MP camera in the iPhone 4S is awesome. It’s been discovered that the iPhone’s new camera is made by Sony, and Apple has definitely been working hard on creating a faster cleaner camera software.

Image quality is pretty nice, although you don’t notice a drastic improvement over the iPhone 4 in most cases. Where the iPhone 4S camera really stands out is shutter speed. Apple’s engineers apparently slaved to shave seconds off the time to takes to actually open and use the camera β€” and the work paid off. The iPhone 4S has the fastest and best quality camera of any smartphone on the market right now.

Macro focus on the 4S works well. It’s fun to take nature and up close shots. Overall, the camera on the 4S is stunning.

1080p video is also a nice addition, and what really takes the cake is the image stabilization technology Apple added. I suspect that image stabilization will be what really separates the iPhone 4S camera from its predecessor and competitors.

Siri is Incredible

Apple hit a home run with Siri. Like most people, I had trouble connecting to Siri yesterday (everyone was trying it at once), but it’s been working perfectly today. (If Siri still isn’t working for you, see this tip.)

Siri isn’t perfect β€” I’m not going to pretend like Apple doesn’t have work to do. First off, Siri needs to have third party app support. Once Apple opens up the APIs (which I’m sure they will), you’ll be able to have Siri order you movie tickets and tell you the score of the last football game. That will be grand.

For now, Siri is about as good as it can be. For a product that’s labeled as “beta” (Apple hardly ever calls its products beta), Siri is better than every other piece of voice recognition software on the consumer market.

What I love about Siri is that she has an attitude. It’s fun to just think of things to say to her. Most of the time, there’s a witty response to laugh at. Apple definitely went above and beyond with adding easter eggs.

Using Siri in public right now is definitely like using the iPad in public when it first came out. I’ve been stopped in public over 4 times today by different people that see me talking to my iPhone. “Whoa, is that Siri?” “Do you like it?” “Does it actually work?” People are fascinated by Siri.

The voice dictation on the iPhone 4S is utterly fantastic. I almost like it better than Siri. Since yesterday, I’ve been dictating about 90% of the things I would have otherwise typed into my iPhone β€” texts, email, tweets, etc. I’m already starting to get frustrated when I need to physically type something into my iPhone.

I’m learning how to dictate properly with punctuation on the 4S. If you don’t specify punctuation, you get nothing but words. Instead of saying “Hey what’s up could you meet me at 6,” say, “Hey comma what’s up question mark can you meet me here at six question mark.” The iPhone will do the rest.

I’ve noticed that speaking slower when dictating will result in faster and more accurate results. When you talk fast, the backend has to parse your language more to figure out what you’re really saying. If you speak slowly and clearly, the server will be able to pick up what you’re saying quickly and spit the text out faster. I’ve said 4 sentence paragraphs with semicolons and parenthesis while speaking slowly, and everything was converted almost instantly and inserted.

Tip: Try speaking emoticons: “winky face,” “smily face,” etc. πŸ˜‰

After using Siri and dictation on the iPhone 4S for only 24 hours, I never want to use another phone without this voice technology. I’m frustrated that it’s not available on my Mac.

Conclusion

The iPhone 4S is Apple’s best phone ever. It’s not leaps and bounds better than the iPhone 4, but it’s certainly worth an upgrade for those than can afford it.

Apple refined the aspects of the iPhone 4 that were already great and added a breakthrough interface called Siri. The iPhone 4S is evolutionary, not revolutionary. And sometimes it’s ok to just evolve.