I just came upon this discussion while trying to find out if the new logging system would tell me whether an instructor gave written feedback on an assignment, along with a grade. (I still don't know the answer to that question...)
I built extensive learning analytic reports on the old logging system using the Configurable Reports plugin, and now I am re-creating those to use the new logging system. What I have noticed so far:
1) I'm not seeing much better detail for the information I want to track. I was already able to tell who was reading forum posts, who was replying to whom, etc.
2) It's quite difficult to compare my old reports with reports that use the new logs-- I don't seem to be able to define criteria that will match the results I was getting before. I realize that more events are being logged (e.g. group creation and editing), but it is difficult to validate my new reports against old reports on the same courses when I can't figure out how to match the logic.
I don't develop modules (yet), so I can't comment on the rant that started this thread, but from a reporting point of view, I'll just say that whatever benefits the new event system is supposed to give us, I'm not seeing them yet. Maybe I'll see more advantages as I continue to work with the system, or as more features and infrastructure are added.