I think now, after the change and the new restriction the situation is much better. I don't really think new moderators /in the English section at least/ are needed. I think we need more time to see if is still needed.
I don`t think that we can talk about any qualitative changes yet. To get (or to buy, or to beg) 1 Merit isn`t difficult, so the number of spammers hasn`t decreased. I believe that new moderators are needed, especially in the English section, since it`s drowning in the waves of shitposts. The peculiarities of the bounty campaigns requirements provide for the majority of posts to be written in the English section, therefore the bulk of the spammers were and remain concentrated there.
In 24 hours, that's 23.3% less posts.
In 48 hours, that's 18.6% less posts.
In 1 week, that's 15.9% less posts.
In 2 weeks, that's 18.6% less posts.
In 3 weeks, that's 22.2% less posts.
OP updated.
The reduction in total posts went up again!
If I ignore the one week before and after theymos' changes, and only look at the number of posts made a week earlier and later (so posts made from September 3 to September 10, and from September 24 to October 1), it went down from 355933 to 280633 posts. That's a 21.2% reduction.
If I ignore the two weeks before and after theymos' changes, and only look at the number of posts made two weeks earlier and later (so posts made from August 27 to September 3, and from October 1 to October

, it went down from 367037 to 260330 posts. That's a 29.1% reduction.