Personally I preffer to use minitest and use dependency injection rather than the magic "allow to_receive and_return" parts of rspec. This makes my code more reusable.

But don't get me wrong, I won't refuse using rspec if it's already set up for a project, just wish it wasn't the go to default. I do believe the ruby + rails code people write would be better architected and more reusable with minitest + D.I. rather than rspec.