There was like 2-3 actually good chibi events out of them all desu. I can't even remember what happened in the most of them, and in the some of them nothing happened at all.
Furthermore, the first events were released as a character packs (Summer Knight and Exodus). Basically the same system as what we have now, considering they were released once in a 1-2 months.

t. day 1 ancient glutti
don't (you) me