I'm still seeing transient slowdowns--but they're better (it actually loaded the pages during the slowdown, just took ~60 seconds). In the fast bits it's doing fine.
Also, with the full front page (before this test) I had noticed that the front page was always much slower than a forum to load (I open front page, general and rules in a tab set--the front page was always last to finish, often by a lot).
Edit: I saw the same lag spike as Charwoman Green, only it took me longer to write my reply.
More: Once the page had loaded after the lag spike, I've been able to post quick replies and do edits all but instantly.