Check out my Debian Stable Vagrant box with pre-installed RVM:https://github.com/jhsu802701/vagrant-debian-jessie-rvm
Unlike the Ubuntu Vagrant boxes, my Debian Stable Vagrant box is low maintenance. The reasons I insist on using my Vagrant box are:
1. Vagrant works in Linux, OS X, or Windows. While Ruby on Rails can be installed in Windows, very few people know how to do this, and this makes it hard to find help.
2. Installing Ruby on Rails manually requires babysitting long processes and takes hours. It's a painfully slow process when you know what you're doing. If you don't know what you're doing (which is likely the case in Windows), then it's even worse. And you can't do anything until you have Ruby on Rails installed - the ultimate waterfall process.
3. How do you make sure that your Gemfile/gemspec and setup instructions for your project are complete? There have been times when a project I started didn't work on a second machine. I've had long cascades of error messages during deployment. This is why I insist on returning to a fresh Ruby on Rails environment. I can do that in my Vagrant box, but I cannot do that when RVM is installed directly on my host OS.
4. If RVM stops working properly or does something that you don't expect, what are you supposed to do? I now just destroy and rebuild my Vagrant box. I don't have to spend time troubleshooting RVM, and I don't have go through the long process of installing RVM again.