TeX Live allows a minimal installation, but what MikTeX has that TeX Live doesn't (AFAIK) is the on-demand automatic fetching and installing of packages. For example, if you `\usepackage{foo}` then with a minimal TeX Live you have to install it manually (with `tlmgr install foopkg`), while MiKTeX will either install it automatically or pop up a prompt asking you whether you want to install foopkg.