Fair enough. For me, the art is improving quality of life and the right kinds of productivity, not improving impulse control per se. It may be possible to train myself to commit to internal deadlines for less-than-pleasant activities without external control. But if I can set external deadlines instead, I don't need that training. The art consists in choosing the right approach while being honest about the costs and inefficiencies. It was the delay in switching to the more effective approach I perceived as lower status that cost me quality of life.

You're right that this is anecdotal evidence; individual difference may account for a lot here.