I personally found Goyo very buggy, bordering on unusable, last I tried it.

Vim Pencil is however great. An alternative, if you want more control over how things look, is to customize linebreak, breakindent, breakindentopt, etc. yourself per filetype (by setting them in files like e.g. ~/.vim/after/ftplugin/markdown.vim).

Every decent text editor ought to have a, "distraction free mode." And in many cases they do. Goyo fills that niche for vim.