If I click+hold and move my mouse fast, then bring it to a stop and let go, the thing spins off into the abyss because it's as if I swiped fast when I did not. I repositioned the cursor to a set point and let go - it stopped and should stay stationary.

If I move my cursor slowly there is absolutely no inertia. If I move my cursor above some arbitrary speed, the thing spins like it's trying to take off. edit: Sorry, there is a very narrow band of inertia levels. Most of the 'slow' mouse movement sits below the lower bounds and so has 0 inertia, and if I go even just a bit faster I exceed the upper threshold and shoot off into infinity.

The first thing I did was try to use my mouse wheel to scroll, like just about every other desktop implementation of such a list. Nothing happened and I wondered if it was just a fixed image I was interacting with wrongly.

edit: FF 38.0.1, Win7 x64, default mouse settings (6/11 slider setting, "enhance pointer precision" acceleration on, presumably 400 dpi on this generic dell workstation mouse).

edit #2: I should clarify: graphically, this is neat and I like it. I haven't tried it on my phone but I sense that it'd work well and look good, but on a PC it just keeps moving in ways you don't want it to and feels all wrong. I keep having to 'catch' the images after flying over them several times.