I was hoping that the OVAs would be character focused episodes. We got a couple of those throughout the series and I think they were a high point. I think the pacing might have been better served if the show was slightly longer. 15-18 episodes, say. Sadly, the OVAs don't do that.
This is one of the few media that address the question: If God exists, why is there suffering, without deciding on either Theodicy (God has a reason and it's X/Y/unknowable) or Maltheism (God is evil and must be defeated.)