On the contrary, I went to PostgresOpen last year and got quite a bit out of it. As a then-new PgSQL user, it really opened my eyes to gotchas, new stuff, ways to configure things, etc. Being narrowly focused allows a much further in-depth set of sessions. Arguably, I might have gotten more out of it than SCALE this year, with SCALE being so broad. I'd have no reservations about attending a similarly narrow conference in the future.