When comparing ASP.NET MVC vs Symfony, the Slant community recommends ASP.NET MVC for most people. In the question“What are the best backend web frameworks?” ASP.NET MVC is ranked 19th while Symfony is ranked 24th. The most important reason people chose ASP.NET MVC is:
The framework has many build-in tools, and many packages have been written targeting the framework.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Mature
The framework has many build-in tools, and many packages have been written targeting the framework.
Pro Cross platform
.Net Core can work on any platform.
Pro Widely used
It's pretty easy to find a job with it and there's plenty of documentation and tutorials around.
Pro Extensive documentation
There are a lot of resources available to get help.
Pro Fast
Asp.NET Core on Linux is fast accordingly to TechEmpower benchmarks.
Pro Asp.NET core provides balance between magic/agility and craftsmanship
You can get ordinary details quickly but with complete freedom to make your craft, knowing everything that is happening underneath the cloths. The highly modular system makes it possible to scale small applications to large ones with ease.
Pro It has more users than any other backend web framework
Getting your next contract is easy with this on your CV.
Pro Open Source
Symfony is open source and released under the MIT license.
Pro Easy debugging with a built-in debug toolbar
Symfony comes with a built-in toolbar that helps developers debug their applications during the development phase.
The toolbar is also extendable and new components, called panels can be added if needed to help with the debugging process.
Pro Great plugin ecosystem
One of the greatest strengths of Symfony is it's amazing and large plugin ecosystem, which comes as a result of it's large and dedicated community. Having a large number of plugins means less development time and more productivity.

Pro Highly active community
Symfony has one of the most active communities out of all the PHP frameworks. This is shown by the high number of commits made every day in the GitHub repo.
Pro Teaches you good practices
Symfony makes you be a better programmer. You have to deal with the latest object-oriented design patterns such as service-oriented architecture, dependency injection, interface abstraction, and so on.
Pro Uses YAML/XML/PHP/Annotation
Symfony makes use of XML, YAML or PHP annotations to create configurations in order to tell Doctrine on how properties of a certain class should be.
Pro Powerful event system
Symfony has a powerful built-in event system that allows you to add flexibility to applications and makes it easier to maintain the codebase down the road.
Pro Great templating engine
Uses Twig, which is a simple and easy to learn templating language that can also be used as a standalone engine, outside the framework.
Pro Uses Doctrine ORM
Symfony makes use of the Doctrine ORM to add an abstraction layer over the database in order to maintain flexibility without having unnecessary code duplication.
Cons
Con Core and full ASP.NET are bit confusing sometimes
While not in feature parity (yet) they are still apart and support sometimes funky combinations of features - full ASP.NET has all the bells and whistles but doesn't offer cross platform so you may have to do some research what you really need. That being said, it got a lot better in 2.0.
Con Expensive
You need to have the plate to maintain a site.
Con Settings
Too many configurations.
Con Very hard to install
Setting it up on webhost without a console is difficult.
Con Promotes bad development practices
Such as annotations via comments.
Con Doctrine ORM
Symfony Standard Edition, which is the most widely used distribution, comes integrated with Doctrine, the most resource hogging ORM library.
Con You need a lot of files to display a single page
For a simple hello world page you need about 5 files.
