Apple iPhone 6s, 6s Plus: Should you upgrade? It depends

They're finally here. After months of leaks, rumors and blurry images, Apple officially introduced the iPhone 6s and iPhone 6s Plus at its Special Event on Wednesday.

Pricing for the updated handsets remains the same as last year's models: $199, $299 and $399 on-contract. The U.S. is moving away from subsidized phone pricing, meaning you can purchase the phones on installment plans through carriers. Or you could simply pay the full retail prices by adding $449 to the contract prices.

Sadly, Apple kept the storage capacities for iPhone 6s and 6s Plus the same as well. That's right, the base model has 16 GB of storage while the next two steps up have 64 GB and 128 GB.

If you currently have an iPhone 6 or 6 Plus, should you upgrade?

For most people, I don't think so.

To be sure, there are plenty of upgrades and new features that only the new phones will have. There's a new A9 processor inside the phones, which Apple says are twice as fast for both processing and graphics tasks. New radios add LTE-Advanced support and speedier Wi-Fi; again, Apple says the wireless connectivity is twice as fast as last year's model.

Also included is the 3D Touch interface, first seen as Force Touch on the Apple Watch. With it, you can "peek" into apps with a soft touch or get a contextual application menu. It looks handy and it's a feature I use on my Apple Watch.

The other big upgrade comes in the camera department. Gone is the 8 megapixel sensor to be replaced by a new 12 megapixel camera that can now handle 63 megapixel panorama pics. 4K video is possible now and the entire iPhone display lights up as a Retina Flash for selfies from the 5 megapixel front camera.

Here's the thing though. As exciting as most of these features sound, they really are incremental from the prior models.

Put another way: Smartphone maturity isn't growing as fast as it did early on in the lifecycle.

A few years back the improvements from faster chips and better camera sensors made a more noticeable difference in the smartphone experience. Now? Not so much thanks to diminishing returns.

My take? If you bought your iPhone 6 or 6 Plus outright and unlocked, it may be worth selling it and applying the money towards a new iPhone 6s or 6s Plus -- don't make the mistake of buying the 16 GB model though, particularly if you plan to shoot many images or videos.

What about folks on contract with their current iPhone 6 or 6 Plus? Unless your carrier has a deal to trade in your old phone for a new one, I'd keep what I had. The one caveat there is if you just must have the latest and greatest that Apple has to offer.

If you are, you may want to consider the new iPhone Upgrade Program directly from Apple. The company will "rent" you a new unlocked iPhone where you can choose your carrier starting at $32 a month. That cost is likely for the smaller iPhone 6s and it does include AppleCare+.

Got an iPhone 5s or something even older? Chances are that even if you bought the phone on contract, you've paid it off by now, or have come close to doing so. In this case, it makes perfect sense to get a new iPhone 6s or 6s Plus.

At the end of the day, all of the "twice as fast" claims are from technical tests and benchmarks.

You're not really going to get twice as much done in a day if you upgrade to the new iPhone. You won't even see 2x Wi-Fi speeds if your home router can't provide them. And while you'll be able to see more detail by zooming in on an image from the 12 megapixel camera, if you simply post photos to social networks, the benefit is lost.

Sure, the new iPhones are nice and a step forward in several ways. And again, there will be people who just bought iPhones 12 months ago that will buy the newest ones again. For the vast majority of iPhone 6 and 6 Plus device owners though, it may not be worth the cost to upgrade.