Frankly, itistoday2 is right - the fact that I have to open an external website and open the multiple pages for the days I've been away, instead of simply scrolling up and continuing the discussion, makes for a terrible experience.

Detachable screen sessions make up somewhat for it, but they're still pretty limited (you might have /joined the channel only later), and it requires a personal service running, that must be attended to & etc.