Sorry you find it tedious. I work with this solution every day and do not find it tedious.
You could work using the pre-compiled release files in VS and perhaps reduce the tedium you experience with the build process. However, if you are new to .NET and even if you are not, the biggest benefit of working with the source code is to learn how it works and the fact that you can easily find good example code for any common development task by studying existing features. If you get the code from svn trunk you also can get bug fixes and new features before they are officially released.
You can also copy the .sn file and rename it and then using your custom.sln file you can remove Data projects for db plaforms you are not using. That can reduce the number of projects in the solution a lot and reduce build time.
Hope it helps,