Why would you be considering a quest time reduction bonus during raid time? Indeed, many of the bonuses are inappropriate during raid time, yet they are the only time it is offered.
These bonuses during raid time force people to choose between taking advantage of the bonus and ignoring the city wide event or putting the city first and ignoring the bonus. It's a terrible choice. Why on earth are these events tied to raid times when there are four other days in which to run it?
My vote is for hearts, because it is completely useless for most players, but at least has no impact on raiding and doesn't punish civic minded players.