The iPhone 6 Plus are impressive

Based on our extensive Lab tests and measurements, the iPhone 6 Plus is the Best performing Smartphone LCD display that we have ever tested. It delivers uniformly consistent all around Top Tier display performance. The iPhone 6 Plus is only the second Smartphone display (LCD or OLED) to ever get all Green (Very Good to Excellent) Ratings in all test and measurement categories (except for Brightness variation with Viewing Angle, which is the case for all LCDs) since we started the Display Technology Shoot-Out article series in 2006, an impressive achievement for a display. The iPhone 6 Plus has raised the bar for top LCD display performance up by a notch.
In particular, the iPhone 6 LCD Plus display sets new records among LCD displays for peak brightness, low reflectance, and several measures of contrast and accuracy. 

DisplayMate finds the iPhone 6 display to have many of the same strong areas of performance as in the iPhone 6 Plus, but the lower resolution and pixel density hold the smaller model back somewhat.
Most rescaled images look noticeably better on the iPhone 6 Plus with 2.1 Mega Pixels compared to just 1.0 Mega Pixels on the iPhone 6. In addition, even at the native display resolution, fine text and graphics look better on the iPhone 6 Plus if you look carefully and closely at the screen (because you may want to or need to). 

The display on the iPhone 6 is none-the-less still a Very Good display, and most buyers will be happy with its performance,And Apple for its specially produced some high quality iphone replacement parts.