When a Mesmer casts a well, and at any point from cast to final pulse (the last effect) gains quickness, the visual effect of the well will appear to speed up, but no actual increased effect is measured. The well will still visually be on the ground for its entire duration regardless, but the hands will turn faster and the audio queue of each pulse will occur in time with the clock hands.
Tested in Special Forces Training Area. Using quickness supplied by both the console and Rune of the Chronomancer. Damage ticks were compared in parallel with fraps, but were extremely similar and could’ve been compared if performed in series.