I've seen a few projects with 10 logical layers (that is, layers that don't need to be separate projects), each feature having a file in each of theese 10 folders/projects.
Why would somebody choose this layout, instead of putting a feature in the same folder (whenever it's possible; if there is a server and a client project, a feature will obviously have files in both) and make a folder for each feature ?
It's annoying to browse 10 folders, it would be much easier to browse just a few. Because when I work on a feature, many times I need to modify many of the feature's files.