I tried Ubuntu 16.04 (kernel 4.4) and would frequently have issues with the trackpad, touch screen and resuming from suspend. Plus the Unity desktop was not completely HiDPI friendly. I've also installed Ubuntu 17.04 Gnome (kernel 4.9) and 17.10 Gnome (kernel 4.10). With each upgrade the laptop would become a bit more stable but still not the level of stability desired for serious field work -- usable but certainly not ideal.
Then I installed Manjaro 17 Gnome... Running kernel 4.14 the laptop has approach near complete stability, on a par with a MacBook Pro. Gnome 3.26 handles HiDPI very effectively and the 4.14 kernel is rock solid on this hardware. I haven't had any problems with the trackpad, touch screen, resume from suspend, etc.. Manjaro is a rolling release so each new major update (and they are frequent) brings with it a bit of a "pucker factor" but so far so good. I am currently running Manjaro 17.1 Gnome (achieved through the rolling release) and kernel 18.104.22.168.
If you have a Dell Developer Edition laptop and you are not satisfied with it's performance, give Manjaro 17.1 Gnome a try. Works for me!