It strongly depends on the maturity of the team. All the comments in this thread are assuming the point of view of the heroic developer and his tribulations. Managers know that some devs will sit on their hands and do shoddy work without constant prodding. A good process has the appropriate amount of incentives to move quickly and checkpoints for quality and accuracy. The more mature your team, the lighter these checkpoints can be. I've found that a lot of teams will essentially graduate from sprint-based Scrum to Kanban once they've acclimated and gained some trust. Same with estimates. They may be necessary at first, but eventually become less valuable.