This sounds very similar to what we are doing. One evening a month.
Subject have been:
Advent
Annulments
Lent
Triduum -- Holy Week
Apparitions of Mary
Pentecost -- The Role of the Holy Spirit
End of Life Issues
We are finishing off our first year of this with evenings for the adults, activities for the youth, and more activities for the families with children. We start all together with a meal and a prayer service and finish with everyone comming back together as one community with a prayer service after the indivudalized sessions for the different age groups.
We also send home additional reading and study for home activities and /or faith formation during the month.
The feedback we have received has been on the fabulous side! (Sorry if that sounds like I'm bragging, I'm not -- merely reflecting the evaluations that are completed each evening.)
We have made some mistakes during this year, but are finding what works and building on it.
It really sounds similar. Except my wife's group hasn't passed out evaluation forms - that really takes some courage!