I've had maybe 1 'bad' (as in people were abandoning to head to fasttrack) queuing experience there fairly recently, but usually it's been swift for the last year or so. Last time there were maybe 4 people ahead of me, time before I think it was possibly just me.

That said I might be atypical as do tend to get there 3-4hrs before flights which tends to mean e.g. 0600 before the rush or late morning/early afternoon (post rush) depending on where I'm going. The one 'bad' was cutting it finer, from memory something like 0800/0900 on a Monday which I'd assume is about the busiest time for business travellers to turn up.