Oh yeah, the touchpad is frankly awful compared to my MacBook's. I've almost considered disabling it, because I keep brushing against it with my palm causing wild cursor behavior and accidental button presses. It's difficult for me to control even when I do it intentionally.

But I don't use the mouse much anyway (hence ratpoison).

The HiDPI screen is pretty good, I talked about it in a sibling comment. Chromium understands the DPI setting and so does Xterm, and honestly I don't use any other programs. I imagine if I used different desktop applications, I'd probably run into some issues like maybe icons being too small or something.

I don't if this is available on Ubuntu, but recent versions of libinput are way nicer than the old synaptics touchpad driver.

Yes, for 15.10 (and 16.04) install xserver-xorg-input-libinput, then edit the config files:

http://askubuntu.com/questions/649103/proper-touchpad-thumb-...

Interesting, thanks!