Apple's iPhone 6s and 6s Plus. Source: Apple. 

A little while ago, I penned a piece explaining why I "traded down" from an Apple (NASDAQ:AAPL) iPhone 6 Plus to an iPhone 6. At the time, here were some of the key reasons I preferred the iPhone 6 to the 6 Plus:

  • The colors/contrast seemed significantly better on the iPhone 6 display than on the iPhone 6 Plus.
  • The user interface seemed a lot quicker on the iPhone 6 than on the iPhone 6 Plus, potentially because the 6 Plus had to render a far greater number of pixels than the 6 did on identical graphics hardware.

Interestingly enough, when I received my iPhone 6s this year, I noticed that the display actually looked quite a bit nicer than the one on my 6. This, coupled with the fact that the A9 processor inside of the iPhone 6s/6s Plus has substantially faster graphics performance than the A8 chip found in the 6/6 Plus, piqued my interest enough such that I wanted to give Apple's larger iPhone another try.

After having used both the iPhone 6s and 6s Plus (I use the former on my personal line; the latter is used on my dedicated work line), it's worth revisiting the comparison between Apple's 4.7-inch flagship and its 5.5-inch flagship.

So, which one should you buy?

The iPhone 6s Plus has a much-improved display
The most frustrating thing about last year's iPhones is that while the iPhone 6 had a significantly sharper display, I found the colors/contrast to be noticeably more pleasing on the 6. Given the choice between the two, the enhanced color and contrast quality of the iPhone 6 won out over the sharper iPhone 6 Plus display.

This year, I'd say the 6s Plus has the better display.

The iPhone 6s still seems to have slightly better colors than the 6s Plus (the whites on the iPhone 6s Plus look a little more "bluish" compared to the 6s, and the blacks still look a tiny bit darker on the 6s), but unless you have both phones side by side and are looking to spot this difference, it's not a big deal.

What is noticeable, though, is that the 6s Plus does have a much sharper display, which I believe gives the iPhone 6s Plus the edge this year in light of the otherwise very close display quality of the two phones.

If Apple is able to do so, I really hope the company can squeeze a 401 pixel-per-inch display into the iPhone 7 to bring the smaller iPhone up to parity with its larger sibling in this respect.

The size question
The other major difference between the two phones is that one has a 4.7-inch display and the other has a 5.5-inch display. Aside from the resolution/pixels per inch difference, the size of the screen impacts the size of the phone. Frankly, this comes down more to preference than anything else, but as a user of both, I'll offer my impressions.

The iPhone 6s simply feels better in the hand. It is slimmer, and for people who enjoy one-handed use of their phones, the 6s is a no-brainer buy over the larger iPhone 6s Plus.

However, I'd argue that people who spend a good deal of time using their phones for light productivity tasks (such as composing email), gaming, watching videos, and surfing the web will be better served by the larger display.

iPhone 6s for mainstream users; iPhone 6s Plus for power users
The way that I like to think about the iPhone 6s versus 6s Plus buying decision is really "casual user" versus "power user." If you use your smartphone for a "little bit of everything" (web surfing, texting, phone calls, causal games, etc.) then the iPhone 6s is probably the better choice, especially if one-handed use and/or the ability to fit the device comfortably into your pocket are key concerns.

However, if you view your smartphone as a full-blown computer in your pocket and use it quite often as such, then you will probably be better served by buying the iPhone 6s Plus.