Why do you make a specific point of the symlink?
Always a good idea to have things you build from source outside your /usr/src tree, and also named descriptively. Not just for stuff you build from source, but also other packages you admin yourself outside the distro package management (JDK comes to mind.)
I can think of a few reasons to build elsewhere like it being easier to do as a non-root user, and so you don't fill a system drive with experimentation, but I'm not quite sure I know specifically why you're saying so.
As for descriptive names, I agree.
My life has been infinitely enriched by the countless hours I've spent, many a dark night, in /usr/src/linux[1], with "Midnight Commander".
[1] A symlink, always a symlink.