What do you like best?
Several Integrated code quality tools like PMD, Checkstyle or Findbugs.
Offer one place of configuration over your codebase
Easy clear UI interface to get a great overview about your code quality from different angle
Easy configuration for plugins
What do you dislike?
Some IDE's plugins not support all SONARQube version, so you should follow which plugin you should use to work properly with the latest versions.
Recommendations to others considering the product
You should identify which kind of quality you try to achieve and pick the right plugin
You can always override SONARQube's default quality settings over PMD, Checkstyle or findbugs, so you can get the most out from this system.
What business problems are you solving with the product? What benefits have you realized?
Easy to integrate into agile workflow by defining / filtering code quality issues and define test for them
By following the suggested code quality problems, you can increase your code quality rapidly.
Thanks to plugins we can use this product to analyze different language based components