I got started with Rails after spending some time learning Symfony2. A lot of the knowledge transferred directly over, and Ruby's syntax is cleaner. Better error messages, too. Symfony's configuration over convention approach probably makes it more flexible than Rails, but I inadvertently messed up the configuration (particularly the namespaces) a lot in the time I spent working on it.

Of course, this was with the S2 alphas and betas. They've likely addressed many of the issues I ran into since then.