I have mentioned this earlier, but I think the smoothing effect in photoshop behaves wrong. THe main smoothing works, but the way it catches up doesn't make sense and is very annoying when painting. What I mean is that you move the brush to a new location, with smoothing on it lags behind, but when you stop the cursor, the stroke stops a certain distance from where you end your stroke. So you have to guess when you should stop paint for the line to stop at the right place. The stroke should have a minimum speed and maximum speed (which is what smoothing % increase/decrease), so it catches up with the cursor like a trail in water or as how inertia would naturally behave.