Three finger drag with trackpad?
Solution 1:
Ubuntu does different: Double tap, but dont release. Is the new three finger drag. Also, it works the same on Windows (not that it matters), and works quite ok for me, for now.
Just had to find out, that was the hardest part.
Solution 2:
Since you don't have unity you should be able to just install touchegg from the Ubuntu Software Center and then for a nice gui you can download and install the touchegg gui from here: https://github.com/Raffarti/Touchegg-gce
Touchegg is awesome by the way! I programmed 3,4 and 5 finger gestures to do anything i wanted. You can program clicks as well as different swipes as well. it's pretty awesome.