Comment 40 for bug 859474

Although the solutions proposed to somewhat fix the problem, they don't do so very effectively. With just the SingleTapTimeout set to 360 click and drag is improved (although not fixed) however single taps get a noticeable delay (which is bearable). Enabling FastTaps seems to fix this for some people, however it makes double clicking quite difficult.

It does seem that the issue isn't so much the default configuration, but the gesture required to initiate the tap and drag. As I said previously, and even with the SingleTapTimeout set to 360, I still need to start dragging before that timeout is up otherwise it won't work. The gesture should be (Tap)+(Press), no dragging should be required to initiate the drag, as when you are trying to do sensitive dragging, arbitrarily dragging before the timeout to initiate the gesture is not an option. A (Tap)+(Press) gesture shouldn't be ambiguous, as a double click is a (Tap)+(Tap).