iPhone 4S carries on the Apple excitement

— -- As the iconic smartphone for these times, any new iPhone would make a huge splash. But coming so soon after the passing of Apple's longtime visionary leader Steve Jobs, it's possible that the freshest model, the iPhone 4S, will attract even more attention. Apple has already announced that pre-orders for the 4S topped 1 million on the first day you could reserve a phone, bludgeoning the previous mark of 600,000 held by the prior-generation iPhone 4. So much for naysayers put off when Apple failed to introduce an iPhone 5.

For a week now, I've been testing the AT&T version of the iPhone 4S in and near New York City and San Francisco. Sprint joins Verizon Wireless as the other U.S. carriers who on Friday will start delivering the device. And Apple takes the finest smartphone on the market to even loftier heights.

Does that mean everyone who owns an iPhone ought to upgrade immediately? It does not.

Yes, the 4S has a superior camera compared with the iPhone 4. And it has a clever and obedient virtual personal assistant named Siri who can frequently detect what you are telling it to do and respond in kind. For example, tell Siri you need to wake up at 7 a.m., and the alarm clock on the iPhone 4S is automatically set.

But most other noticeable enhancements arrive starting Wednesday as part of free software upgrades available to owners of the iPhone 3GS and iPhone 4 (not to mention the iPad, iPad 2 and recent vintage iPod Touch models).

The new software is the iOS 5 mobile operating system, which introduces more than 200 features, including a handy and unobtrusive way of delivering notifications of texts, e-mails, missed calls, stock prices, appointments and more. All you need do is swipe down from the top of the device, not unlike on Android phones. And you'll see notifications on the iPhone lock screen.

Twitter integration also arrives with iOS 5, as does the iMessage service that lets you send texts, photos, videos and locations to friends or contacts who also have iOS 5 devices. The beauty of iMessage texts compared with standard SMS messages, is the ability to receive receipts when your message is delivered and (sometimes) read, along with an indicator when someone is typing a response. And iMessages don't count against your regular texting allotment.

With iOS 5, you also get iCloud, Apple's digital hub for the Internet age. ICloud combines an online storage repository for your music, videos, pictures, e-mail, contacts, calendars, apps, books and more with a free service that wirelessly pushes this stuff to your Mac, PC, iPod Touch, iPad and iPhones from the 3GS on. The goal is to keep everything in sync, readily available and up to date.

The latest iPhone costs $199 for a 16-gigabyte model, $299 for 32 GB and $399 for 64 GB — all with a two-year voice/data plan. Only iPhone newcomer Sprint offers new customers an unlimited wireless monthly data plan, starting at $69.99 (plus a $10 premium fee) for 450 voice minutes on up to $99.99 (plus $10) for unlimited voice minutes.

Verizon's entry-level $69.99 combined voice and data plan gives you only 2 GB of data, along with 450 voice minutes. AT&T has a $15-a-month data plan that gives you only 200 megabytes of data or a $25 plan for 2 GB. You'll need to tack on a voice plan that starts at $39.99 for 450 voice minutes. (Both AT&T and Verizon let customers who previously signed up for an unlimited plan keep those plans.)