Personably I started using Arch because of its excellent Wiki, after three Fedora updates in a row failed on me and I found myself over and over in the Arch Wiki getting answers.
But my post was primarily focusing on the experience of building / modifying packages. To elaborate just a bit more as an example, the Debian docs claim one can use this environment variable to control certain things when building a package.
DEB_BUILD_OPTIONS='nostrip noopt debug'
What they don't mention, is that these environment variable values are only enabled on a case-by-case basis for every package. Which means, you can't just expect to be able to easily rebuild an arbitrary package without cleaning first, i.e. doing an incremental build. You have to look at debian/rules, which is highly unstructured (unlike PKGBUILD), uses tons of DEB_ makefile variables which I have no understanding of.