So wait, if I choose to convert to using Module::Build not only do I inconvenience all of my users who dont have Module::Build, I also lock out the ones who can't get it to work, and as an added bonus get to spend hours converting non trivial Makefile.Pl's over to Build.Pl framework? Gee sign me up.
So don't freaking use it. Sheesh, no one has ever said "run out and convert all your existing modules, especially the ones that have heavily customized Makefile.PL files".
OTOH, if you're writing a new module, or looking into adding custom bits to a Makefile.PL for an existing module, then Module::Build is probably worth looking at, as creating a customized build/install process with it is much, much easier than with EU::MM. I've done both, so I'm in a good position to know.