With comments like this, and the earlier comment by someone about Edler being the most complete defenceman on the team, I think people are watching a different team than I do. Edler hasn't been a significant difference maker in the playoffs since his injury, while Hamhuis and Bieksa have both been the real drivers to any success the team has had in the playoffs.
Edler is good, but in the playoffs, I actually rank the stronger defensive players above him (Bieksa when on, Hamhuis, Garrison and Tanev).
Also, I think Bieksa and Hamhuis are pretty clearly more complete players. Edler is the most elite offensive defenceman on the team, but he's not the best or most complete.
I think the suggestion of playing him 18-22 minutes is the right one. Let the other defencemen carry the heavy defensive minutes, and help Edler drive the offensive engine.