There are various people who feel that Lesswrong degraded in the last year. In the same timeframe more and more discussions moved into the open thread model and open threads became weekly instead of monthly.
I suggest to counteract that trend by opening all discussions per default on Discussion instead of opening them in weekly open threads. Having the topics in discussion makes it easy to browse the list of topics and choose the headline that are of interest, even if the thread got opened two weeks ago.
I think LW's degradation is primarily in Main (interesting Main posts are rare these days), and has nothing to do with Open Threads. If anything, Open Threads help LW because they make community participation easier with a lower barrier to entry for posting.