This job was a serious challenge for all of us. The home-owner expected miracles for a very short time (just before the holidays), and we had to deal with badly damaged flooring. Indeed, it's not a big deal, but the time-frame is always important.
However, we did the necessary repairs (which took 7 hours), and then the sanding was made at a glance. The final touch was finishing with sating lacquer, and right now the flooring looks like new.
The entire job took 2 days and a half.