I think there are still strong advantages to the centralized locking style of collaboration. The challenge is that it seems to work best in a setting where everyone is in the same physical location while they are working. You can break a lock in 30 seconds with your voice. Locking across time zones and date lines is a nonstarter by comparison.

It seems like in a reasonable sized org you should not be merging so often that “centralized locking … across time zones” should be an issue.

Are people really merging that often? What is being merged? Doc fixes?