I have seen very similar symptom on my 9365. Windows updated, latest drivers and BIOS via Dell Command Update and my trackpad/mouse experience had intermittent lagging. I tried the disable/enable steps above on the HID devices, but that did not solve my touchpad lagging. I found another thread on the web on disabling C-States in the BIOS. After disabling C-States in the BIOS, my touchpad experience has dramatically improved. While it is too early to call it fixed, this is the most promising improvement I have seen with my particular experience.