Thanks. Like I said, I started almost from scratch, so it was easier to learn new habits (didn't really have to get rid of bad ones). By my own calculations, I must have hit about 4000-5000 volleys during this 4-month period.
I guess the next step for me is to hit more volleys during hitting sessions and matches (which will need a lot of adaptation and represents another part of the learning curve). And I'll try to hit volleys in a «controlled environment» at least once a week, to make sure I dont' develop bad habits.