I have the xps 15 9550. Track pad is a bit slow but you can alter the speed of the mouse movement under Mouse settings. Under Settings for windows 10 there is also trackpad settings too. I didn't notice much of a difference messing with those settings but you can have it change the scroll speed in applications. I have gotten used to it.
Love this laptop but its going back to Dell for repair. The speakers are freaking loud which is good but they crackle when turning up the volume from the taskbar, not from the key buttons, and the screen flickers at 10% brightness.
In addition Dell wanted me to do a factory reset on the system and I found out my recovery partition was messed up from the day I received the system. I have the 256 pcie NvME ssd model so they sent me a Dell USB with windows 10 Recovery on it but it is telling me it can not find the recovery drive or partition. So I have to send it back for them to replace my ssd it seems and possibly check speakers and screen.
Which is weird too because I'm typing from it now and it boots to Windows fine, but I guess I would be screwed if I ever needed to reset it to factory defaults.