The manual install guide is good to go, but the stage4 install guide is still being worked on.
I just took a look at the last time Buzztard was modified. The project web site is gone and the project on which it is based, Buzz, has evolved since then. So Gentoo Studio will no longer include Buzztard as part of the manual install guide or stage 4 tarball. There are more updated trackers available either free (e.g. schism-tracker) or commercially.
I have been working assiduously on completing the updated manual install guide. It's taking longer than expected because I'm juggling several major projects at once, and I like to be conscientious. That said, while I am leaving the "do not use" warning up until I'm completely finished, you are welcome to begin using it. I have gotten as far as the "installing audio software" page, so you should be OK. There are a couple of changes I will go back and make, but nothing deal-breaking. As always, PM me (audiodef) through forums.gentoo.org if you need help.2016-08-03
The following error is known on system other than Gentoo. I have not seen anyone post a solution as yet, so there may be nothing we can do but sit tight and wait for the developer to release an update.
/usr/lib/gcc/x86_64-pc-linux-gnu/5.4.0/include/g++-v5/functional:1167:64: error: no match for call to '(const volatile sigc::bound_mem_functor3
) (SooperLooper::Engine* const volatile&)'