Dell Latitude E7470

Hardware Overview

CPU: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz (2808.14-MHz K8-class CPU)
Wireless: Intel Dual Band Wireless AC 8260, supported by iwm(4), works
Wired Ethernet: Intel(R) PRO/1000 Network Connection 7.6.1-k, supported by em(4), works
Graphics: Intel Skylake, supported by drm-next branch, works with some issues with external connectors
Sound: Realtek ALC293, works, also correctly detects plugging in the headphones
Suspend/resume: untested
Fn keys: only toggling keyboard backlight works; other keys (volume, display brightness, wifi toggle) do not

Add kld_list=“if_iwm” to /etc/rc.conf
Display brightness is too high by default. It can be tuned with https://github.com/FreeBSDDesktop/intel_backlight_fbsd, but it's reset when display goes to sleep. I've ended up by tuning it in the BIOS.
May also add coretemp to kld_list

Problems with plugging/unplugging external monitors
- You may need to restart xorg to make all external video outputs detected
- When you disconnect all external outputs you cannot get them back until reboot
- See https://github.com/FreeBSDDesktop/freebsd-base-graphics/issues/155

Don't forget to add your user to video group for xrandr to work properly
Removing xorg.conf is also recommended, as having it may interfere with dynamic detection of external displays and lead to system panics.