Just do it, get used to it, make it work for you.
It is awesome and the only way to go … but it takes a different mindset and work flow to use correctly.
Everything I do is in the context of RVM, and so will the instructions in these cheatsheets. Even my projectspace has its own gemset. Be sure also to set RVM default gems for all new gemsets; it saves a lot of hassle.
Currently, I only use Ruby 1.9.3.