I program in Ruby a lot, have done for a long time, and love it, but I've also lost weeks (months?) of my life to fighting gem interdependency problems and watching 'bundle install'. It's almost certainly my least favourite part of the job.
That's not to denigrate the efforts that go into RubyGems, Bundler, etc. - they're doing a good job, and they make life much easier than it would be without them, but in some ways they're playing with a lousy hand for historical reasons that are too late to change now.
I'm largely ignorant of Symfony2, but I hope it's learning from the flaws of the RubyGems ecosystem as well as its strengths.
We're considering a switch to RoR (from CakePHP oddly enough) at my job, but this gem dependency nightmare gives me pause. I ran across rvm in my research, and it's supposed to solve these concerns. I'm wondering if you have used rvm and whether or not rvm solves the problems you've run into in the past.
In short, no. I've used it, but I think that the problems that RVM solves are largely orthogonal to those.
I don't use (or need) RVM on servers, and I don't use it on a daily basis, but I find it useful for testing gems across multiple interpreters before I release them.
