6s pros:
Smoother due to lower resolution
Slightly (~ 10% difference) better display contrast/colors
Easier one-handed usage
Smaller footprint
6s Plus pros:
Larger battery
Sharper, larger 1080p display
Superior for portrait typing
Optical image stabilization
The 6s is incredibly smooth. Makes me want to compare to the 6s Plus further before switching back to the Plus size. It seems at a very conservative minimum twice as smooth all around over my 6 Plus, whereas my 6 Plus has a very noticeable lag present throughout the interface.
Smoother due to lower resolution
Slightly (~ 10% difference) better display contrast/colors
Easier one-handed usage
Smaller footprint
6s Plus pros:
Larger battery
Sharper, larger 1080p display
Superior for portrait typing
Optical image stabilization
The 6s is incredibly smooth. Makes me want to compare to the 6s Plus further before switching back to the Plus size. It seems at a very conservative minimum twice as smooth all around over my 6 Plus, whereas my 6 Plus has a very noticeable lag present throughout the interface.