I love how fast it can build tests, automate them with multiple languages/locales etc., but also have access to all of our codebase in one place! The interface is not that great for non-technical people (although there are workarounds). Also very expensive compared other testing tools out here like TestComplete or Loadrunner which do support more than 2 platforms at once as well - so if you want your test suite fully automated across different browsers / operating systems then qa engine might be too much right now? We use this tool primarily together wtih automation agents from Selenium Webdriver running browser simulations against various web applications such us Angular2+ sites we develop ourselves using Typescript syntaxes + NodeJS API calls where needed.