After talking to Allen Briggs about progress(1) and pipes, I'm
wondering if tar -B should be the default if it is indeed reading from
a pipe.  I admit, though, I don't know what the rationale was for
making this optional in the first place other than perhaps historical
compatability.  Would it be reasonable to make -B default and instead
add an option to disable it?

I notice somewhat better performance (especially with LFS) using -B with pipes.

Regards,

--Blair