i found a workaround on my linux x220, basically there is a noise setting in the synaptics driver that filters electrical noise from the touchpad, as far as i understand, the noise comming from the x220 touchpad is greater than normal hence the jumpiness
there's 2 ways to set it, the first with synclient (man synclient and run it without options would list all) and the Horiz/VertHysteresis settings, this one didnt work for me because i dont have those 2 variables in synclient, but listing for posterity in case this would work on some other linux distro
the second one which did work - you need to list your input devices in X:
$ xinput list
⎜ ↳ SynPS/2 Synaptics TouchPad id=10 [slave pointer (2)]
$ xinput list-props "SynPS/2 Synaptics TouchPad"
Synaptics Noise Cancellation (288): 6, 6
- that 6,6 setting is too low, upping it to 24,24 or 32,32 or even 64,64 will fix it, try lower values first because the higher you go, when moving the finger on the touchpad the mouse pointer wont move as smoothly (seems like its jumping pixels)
$ xinput --set-prop "SynPS/2 Synaptics TouchPad" 288 24, 24
you need to run the commands as the regular desktop user since they need to access the X server connection
i dont use windows so i have no idea how to workaround it there, i imagine there might be a similar setting in the advanced driver settings
this is still a workaround and not a fix since it affects mouse pointer movement, i think i would have a hard time doing simple design fixes in gimp for eg with the touchpad, something i was able to do when this didnt happen
