Thank you, so Rails would be a front runner choice for you when developing a new web application?

Rails continues to include things that most developers need when building a web application or api.

While most people are arguing about web framework speeds Rails has been putting in features that are useful, like mail previews, strong params, async emailing, Russian doll fragment caching(nice if your still doing traditional templates, can be used with JSON rendering too). The community also has very nice and mature libraries for doing authentication, authorization, audit trail, and uploading.

Not to mention, testing is in out of the box.

Use the right tool for the job. If your project is just a REST api then Rails might not be the right choice. If you're writing a complex CMS/CRM,ecommerce site,or anything that has a complex UI from scratch, then rails and ruby's gigantic ecosystem will set you up and running in no time.

But so can Spring,Django or Symfony if you know them from the inside out.

It depends. But yes, Rails is certainly "still relevant".