Does statically linking everything not lead to much higher disk usage, espcially when you have thousands of binaries? Drew Devault has an analysis[0] that appears to claim otherwise.
That analysis doesn't really answer the question re: disk usage and doesn't really quantify how much sharing there is from shared libraries, just how many shared libraries don't get shared... basically "Do your installed programs share dynamic libraries" is answered as "not really" because there s a long tail of libraries that are not widely shared.
Drew's stats shows 80% of binaries link to libc (1.8MB on my system), which by itself could be "a lot" of extra storage. It wouldn't be 80% * 1.8MB per executable if unused symbols weren't linked, but still