Solution Folders in Enterprise Library

Solution Folders are a small but very useful new feature in Visual Studio 2005. If you haven't stumbled across them, they let you group the projects in your solution into a logical hierarchy, rather than have them all at the same level. They are particularly useful for solutions with a lot of projects - and Enterprise Library does have quite a few projects.

We've been trying out a couple of alternatives on how to use solution folders. Here are the options we're considering:

The two options are pretty similar, with the difference being on how the unit tests are organized (note that unlike EntLib 1.x, all unit tests are now in their own projects rather than in namespaces under the existing projects).

Option A has all of the unit tests grouped together under their own root solution folder. This means you can easily close this folder up if you don't want to see the unit tests. It also means that the unit tests are not really grouped anywhere near the code that they demonstrate - so it may make it harder to switch between the two.

Option B groups the unit tests together with the main projects. So they are harder to ignore (which may be a good thing or a bad thing, depending on your perspective), but they are always close to the code that they are testing.

Which would you prefer? Or if you have any other suggestions, that's fine too!