@OP: What other devices do you use? iPhone 6s screens are top notch compared to 98% of LCDs out there. Granted I feel like Apple's screens have fallen behind compared to the latest and the greatest - such as flagship offerings from Microsoft, Samsung, and Google. Still those are exceedingly few and recent products. Unless you are surrounded by Surface Pros, Galaxy phones, or Nexus/Pixel line of products, Apple's screen should stand out nicely.
An exception is the iPad Pro's display which I thought unacceptable for the price. At anything below near max brightness, the screen suffers a lot. The best display among Apple's i-Devices as of 2015 belongs to the iPad mini 4.