If your question pertains to whether you should opt for the new iPhone 7 or 7 Plus, here I go with my arguments about the features.
Design and size
In terms of design, there has been no change in iPhone 7 and 7 Plus. The external looks remain same as the previous devices with just a few subtle changes. The latest Apple smartphones now comes with IP67 water and dust resistance capacity. Home button is now capacitive and the feel is quite great according to the users. The antenna lines on the rear are gone which gives the phones a cleaner appearance.
Bye Bye 3.5 mm Audio jack
Considered to be a controversial decision, the 3.5 mm audio jack has been done away with. It is now replaced with lightening Port. It would mean you will need to search for the specific headsets complying with the standard ( Apple provides the adapter within the box as of now, but I would not expect it to continue doing it forever). Also gone are the chances of listening to music and charging your phone simultaneously. The 3.5 mm audio technology has gone obsolete and provides you an inferior audio quality, that has been the reason why Apple decided to remove it. Moreover, Apple has stated that the feature had to be removed in view of providing effective water resistance properties (How other manufacturers have been providing water resistance along with 3.5 jack is a puzzle for me - Maybe Apple can explain it!)
Even as Apple is ditching audio jack stating it to be old technology, they are continuing with the LCD display when other manufacturers have been moving on. There are reports that the LCD technology has been pushed to its extreme to provide you the best possible performance. The color reproduction has been the best so far as long as the Apple devices are concerned.
One should note that Apple has lost the title of being the best camera phone to Samsung in recent years. iPhone 7 comes with a 12 MP camera, while the iPhone 7 Plus offers you a dual camera setup with a telephoto lens. Optical Image stabilisation has made its way in the iPhone camera set up. There is also a 6 element lens as compared to the 5 element lens on iPhone 6 and 6 Plus. Color accuracy and low light camera performance has been improved. That, however, does not mean that the Apple devices have regained the topper slot in terms being the best camera, yet - yes, the difference has been much closer.
Live....and Let Live!