Macbook touchpad cursor moving "in steps"

[undertakingyou]

I was having the same issues but noticed that when I did a fresh install the issue wasn't there so, I selectively edited my xorg.conf to get what I feel is a smooth scroll and tap-drag speed etc. Here is my section:

Section "InputDevice"
    Identifier	"Synaptics Touchpad"
    Driver	"synaptics"
    Option	"SendCoreEvents"	"true"
    Option	"Device"	"/dev/psaux"
    Option	"Protocol"	"auto-dev"
    Option	"HorizEdgeScroll"	"0"
    Option      "VertEdgeScroll"    "0"
    Option      "TapButton1"        "1"
    Option      "TapButton2"        "3"
    Option      "TapButton3"        "2"
    Option      "VertTwoFingerScroll"   "1"
    Option      "SHMConfig"         "on"
EndSection

This makes it so you use two fingers for right click and three fingers for middle click. It also adds the two finger scroll.
Now you could add the lines for Horizontal two finger scroll etc, but I find that one rather annoying so I don't do it.
Anyways, I hope that helps.