After having used Visual Studio for years, we switched to Webstorm in 2014. We're all a big fan of this IDE: the code assistance and debugging/testings options are truly magnificent. The only big downside of the tool is when your projects starts to grow and you've got a lot of Node dependencies in your project. The IDE freezes all the time, making it impossibile to work with. Although there are some ways to exclude your Node modules from being indexed, I choose to code in Sublime when working on large projects.
When I was reading up on the new features of the recently released version 10, I was a bit dissapointed. Sure, a distraction-free mode is nice, and simultaneous HTML tag editing can save you some time, but they are not really reasons for me to upgrade.
I've tried to work with some of our larger codebases that previously made Webstorm freeze, and it turns out that these projects indeed work a lot smoother in version 10! I'm not sure of how they changed the inner workings of the indexing proces, but I think they did an awesome job. There is still some room for improvement. Maybe they can only index direct dependencies, instead of also indexing the transitive ones?