One aside: its a lot easier to go "yay, stocks are down, I'm buying them cheap" when you're in the accumulation phase.
Good article - but I agree with Arebelspy. I am still in accumulation mode and fluctuations don't bother me much and with a bit of reallocation/timing may be beneficial.
But if I was FIRE then I worry how I would handle it (psychologically speaking) say if I have a $1,000,000 nest egg and live off of $40k - 4% SWR and then we get a 15% market drop (not crazy, not unrealistic) and now I have $850,000 and either have to live on $34k or deplete more principal. I don't know if I will be stressed or not....my personality type leads me to beleive I would be stressed on one hand but confident that it will work out on the other due to market recovery, side work, going back to work, etc.