The others are even worse. I tried using OMake and apart from having some neat features like watching files and automatically recompiling it was an incredible pain of setting it up - mainly due to the strange programming language used in its build files. Also, it has seen 0 updates in the last years.
It already starts with the compiler, calling them manually is quite a pain, especially if you want include any kind of library, which is why ocamlfind is such a huge win.
Oasis isn't that bad apart from a few options that are tricky to get (or the fact that, as far as I know, there's no sane way to make it install executables to your ocamlfind directory, which makes it fairly unsuitable for PPX extensions). For the most part, it's about as easy/intuitive as using Cabal.
Yes, I am using it too, but too bad it is basically unmaintained since its author moved to work for Google. I had hoped it could generate many more files like config for Merlin or Makefiles for build systems than ocamlbuild.
It already starts with the compiler, calling them manually is quite a pain, especially if you want include any kind of library, which is why ocamlfind is such a huge win.