It was great for large projects. I worked on a project that was similar to Android. Imagine 10 device trees (device drivers), two OS trees (Linux, vxWorks), a

It was great for large projects. I worked on a project that was similar to Android. Imagine 10 device trees (device drivers), two OS trees (Linux, vxWorks), and two application trees (the old stuff, the new stuff). You could define a mapping that got you just the trees you needed, which both sped up builds and VC operations (although p4's local indexing made most VC operations lightning fast). Imagine a world where 'svn up' or 'cvs up' takes 20 minutes. Not only did the client mappings limit the scope of the operations, but local indexing brought the time for those operations down to 0-4 seconds.