Vim-plug just requires a single file download to start using, and also requires nothing extra be added to your Vimrc outside of the function calls to start/end defining plugins.
vim-plug allows you to automatically run arbitrary shell commands after installing or updating a plugin, which is useful if the plugin needs to be compiled or make installed after an update.
Other plugin managers will install, enable, and disable plugins for you. This one doesn't. If it's in the bundle directory, it gets loaded, if it's not, it doesn't. This can make it difficult to debug which plugin is causing some unexpected behaviour, as there is no simple way to enable/disable loading a plugin.
Janus is a great place to start with Vim, with much of the functionality that you would expect from a modern editor, without you having to configure it all.
Output is displayed in the quick fix window, errors are matched with error format. After a job is finished, it can ring a bell to notify you while you're focusing on editing.
Command is done in the background, no need to wait for the entire process to finish. You can explore the error output immediately, or keep working in vim while executing.