Ok, having just dabbled with this on breadboard for a short while, my immediate thought is that the wait for the finger being lifted from the switch, ever so slightly delays the led from lighting up instantly... which makes the actual switch depress feel a tad unresponsive.

Without the wait, then there's obviously going to be another interupt when the finger is removed - but is this such a concern? - can't this second interupt be ignored with dedicated code?