Finished rewatching Angel Beats!.
It's not as bad as I gave it credit for before. One character was completely unbearable from start to finish (Yui), the show had too many elements going on at the same time, and the show was just not long enough to fully develop its more interesting cast. That and the final conflict is introduced and resolved far too quickly. However, despite this, a lot of it worked, particularly in the area of characters it did develop, without heavily relying on manipulation (so much emotion in AB! was rather genuine) and having a rather mature message underneath everything. It's not a quiet show in the slightest, but it does convey its purgatory ideas rather well. Nowhere near perfect but definitely not a bad show.