I think this is all I would want before considering to try reggae
as my main build system. Concept worked pretty good so far and I
feel very satisfied with what we can potentially get from it -
though, I must admit, I haven't tried to port any of more
advanced makefiles to it.
I'd suggest to try reimplementing DMD/Phobos makefiles with
reggae once you are confortable with a design to see if it really
works up to expectations. These contain some rather nasty rule
mess and can serve as both great playground for checking design
choices and selling point in improving simplicity / clarity.