I can tell you that my experience with the priority bags has worked well in both Tampa and Portland this week, so I believe that this perk will work well.
As for the boarding perk, since non-elite passengers sitting in the bulkhead seats get boarded in Zone 1 anyone boarding in Zone 2 can find the overhead space in the first few rows already limited. This new change should help those DM, PM and GM a decent shot at the overhead space in the first few rows of coach.