rvm will download the requested version's source, apply any patches or flags you specify and then compile it. You don't have to do any work other than installing rvm. The rubies are also stored in ~/.rvm so your system doesn't get cluttered up.
Rvm also integrates into your shell so that when you cd into a project directory with a .rvmrc file, it will source the file and load the proper ruby and gemset for that project.
Virtualenv is much closer to ruby's bundler gem than rvm.
