This means that collision detection between two different machines now works reasonably well; it also means that no file server or directory can become a bottleneck.
The new method does have drawbacks. It means that collision detection does not operate when you edit a file in a directory where you cannot create new files. Collision detection also doesn't operate when the file server does not support symbolic links. But these conditions are rare, and the ability to have collision detection while using NFS is so useful that the change is worth while.
When Emacs or a system crashes, this may leave behind lock files which are stale. So you may occasionally get warnings about spurious collisions. When you determine that the collision is spurious, just tell Emacs to go ahead anyway.