Recs.
Updated
SpecsUpdate
Pros
Pro Smart refactoring
IDEA places an emphasis on safe refactoring and offers a lot of features to make this possible for a variety of languages.
These features include safe delete, type migration, and replacing method code duplicates.
Pro JS code context-awareness
This warns you when you forget to declare "var" (duplicate declarations). Variable name refactors occur within the function scope and IntelliJ warns you when you use a variable that hasn't been defined. It also has integration with JS linter plugins (like JSHint) for additional static code analysis.
Cons
Con Requires a lot of memory
IntelliJ requires much more memory than Sublime Text or Atom.
Con Requires a license for its use
The commercial-use license is a hefty price of $500 USD, while the personal-use license is $150 USD. There is, however, a 30-day free trial period available.
Con Standard hotkeys behave differently
Seems like hotkeys assignment in Idea has no logical consistency.
Like «F3» is usually next match, «Ctrl+W» - close tab, etc — they map to some different action by default.
There is a good effort in making the IDE friendly for immigrants from other products: there are options to use hotkeys from Eclipse, and even emacs. But these mappings are very incomplete. And help pages do not take this remapping into account, rather mentioning the standard hotkeys.
So, people coming from other IDEs/editors are doomed to using mouse and context menus (which are rather big and complex).
Con Somewhat expensive
IntelliJ IDEA is fairly expensive, with a pricetag of $149/year.
However there is a free community edition available.