Once you start shipping to production you care far less about "speed of development" and "prototyping things" and more about "does this actually work".
Don't get me wrong, Sails might be very good for prototyping something, but I could recommend it only if your only goal was to prototype something.
Don't get me wrong, Sails might be very good for prototyping something, but I could recommend it only if your only goal was to prototype something.