Jess Martin writes about task management with Trello (but only tangentially references actually using Trello):
You might think it’s working. You might even be considered effective at your work. Someone might have once called you a rock star or a ninja. You might not find out that it’s not really working until you get that promotion you’ve been craving. Or things get busy at home. And then you’re stuck with a broken system, underperforming in your new role, overwhelmed at home, and you’re wishing you could just go mow a lawn.
I think this is right on. Slow work is easy to track in my head. It's the crunch times that blow everything up.
By way of @Potatowire and his fervent love of Medium.