I have used Rails for most of my career and for a number of side ventures. I have to say I have had a love-hate relationship with it.
I love everything people love about Rails (mentioned above). What I hate is how the speed and productivity comes back to bite you later.
The code eventually turns into a ball of mud and becomes near impossible to update. You have N-dependencies that depend on Y-dependencies of their own. Different Rails versions or module versions, and you can't update one without breaking something else.
You eventually live with it, and nothing gets updated but then you want security updates, and sometimes something terrible happens (like the mimemagic catastrophe) that forces you to ham fist updates together and live with some rails engines not working completely. But that's ok, because productivity right?