After much media attention and a little disappointment that it isn't the iPhone 5, the iPhone 4S finally hits the shelves today.

Some people must be wondering if the iPhone 4S worth getting or should they wait until the hype machine starts talking about the iPhone 5? Timing is everything because wireless networks make you wait two years after you buy your first iPhone until you are able to upgrade to your second.

You can upgrade earlier than the allotted time, but then you will have to shell out full price. That can be a $450 difference. Since new iPhones seem to launch every year this can be quite the conundrum. Whether or not you should buy an iPhone 4S depends on what you have now and how long you can wait for an upgrade.

If you are eligible for the reduced price it either means you are getting an iPhone for the first time or you are upgrading from either the original iPhone or the 3G, or 3GS. When you are getting a 2-yr contract rate you have a few options: a free 3GS, a $99 iPhone 4, or the iPhone 4S for $199 (16GB), $299 (32GB) or $399 (64GB). The free 3GS and the $99 iPhone 4 both come with 8GB of internal memory.

So what do you get with the new iPhone 4S over the others? The major upgrades to the new phone are an 8-megapixel camera and the new and powerful dual-core A5 chip. The new chip makes it twice as powerful and provides seven times more graphics speed than the iPhone 4.

The iPhone 4S is also the only smartphone that can run Siri Voice Assistant. Siri is a voice command feature that can pretty much interact with any component that comes on the iPhone. It can make calls, write texts, set the alarm, find restaurants and search the web. It is pretty neat, but there are some bugs that still need to be ironed out.

But truth-be-told, the iPhone 4 and 3GS both share in the best upgrade the iPhone 4S is getting: the new iOS 5 that released Wednesday. The iOS 5 is Apple's latest mobile operating system features improvements to Safari, the phone's notifications and the camera interface. It also introduces the iCloud to mobile devices.

So if you are eligible for a new iPhone at the reduced price you should probability go for it. The iPhone 5 won't be out for at least a year, if they stick to their current development cycle. The iPhone 4S has enough upgraded features to justify an upgrade from the 3GS or whatever other device you want to switch from. And by the time you are eligible for a new upgrade, the iPhone 5S (or whatever they will be calling it) will either be out or just around the corner.

If you already own an iPhone 4 and you feel the urge to upgrade, I wouldn't recommend it. The iPhone 4 stands up pretty well to the iPhone 4S and the only thing the 4 seriously lacks from the 4S is Siri and a little extra horsepower. Since you have an iPhone 4 you probably aren't eligible for a reduced price yet, so it will cost you some extra money. Also most carriers reset your eligibility even if you buy the phone at full price. And that will come back to bite you when you're feeling iPhone 5 envy next year.