Created attachment 128947 [details]
Updating from 1.5.3 to libinput-1.5.901-1.fc25.x86_64 makes the speed of the touchpad really slow on a Dell XPS 9550 (2016/Skylake) with high precision touchpad really slow.
In order to make it rather usable I had to turn up the acceleration in system to max.
Created attachment 128948 [details]
One finger movement from right to left in about less than a second at max acceleration setting moves cursor to about 75% distance from right.
Created attachment 128949 [details]
Info for Dell Touchpad (/sys/class/input/event15). Also added info for event7.
# cat /sys/class/dmi/id/modalias
Notice it was an entry for this bug already. I have a Full HD screen as well so it's not related to HiDPI
*** This bug has been marked as a duplicate of bug 99383 ***