I still use isolated $GEM_HOME directories for each project on my dev machine, and don't rely on bundler to separate installations on production machines. In m

I still use isolated $GEM_HOME directories for each project on my dev machine, and don't rely on bundler to separate installations on production machines. In my mind, bundler was never really needed for that - it was a complexity step further than was required - so I never set myself up to rely on it, instead relying on a simpler mechanism which doesn't need runtime tooling support. As a result, I never have to run `bundle exec`. How much you might prefer this will probably be more dependent on how much you appreciate simplicity.