If you're interested in TypeScript at all, the two were made for each other. I'd suggest giving it a try.
Just note it's closer to a text editor with IDE functionality, rather than a full-blown IDE itself.
VSCode is an Electron app, that means that it is written in Javascript and HTML5. Electron apps are notoriously resource intensive even though their UI is typically responsive. Watch your CPU usage spike and battery life plummet as you use Electron apps.
Even the Slack messaging client (another Electron app) can spike a CPU under certain circumstances. And that is a simple messaging client that doesn't have to parse and markup code like an IDE does.
No. Pretty much the same as Notepad++.
WebStorm beats VSCode hands down in refactoring though.
When I first began using it the lag made it unusable. I'm talking up to 2000ms delay for visual feedback on my typing. Somehow that resolved itself over time though, and with my newer rig it's actually pretty damn snappy. It only takes about 15-20 seconds to spin up a virtual machine and launch Webstorm. I can't imagine how quick VSCode might be for me. I'll have to try it out tonight, everyone here has convinced me it's worth checking out.
You get most of the features from a heavyweight IDE, but they managed to get the architecture incredibly lightweight so you can use it as a "daily driver" editor as well.
It is snappy enough to quickly edit some configuration or Markdown files (with live preview and clickable links), it has text based configuration files, its easy to write plugins with a couple of lines of code – and all sorts of other things that previously could only be found on the "editor-side" of the spectrum (export VISUAL="code -w", anyone?).
Unique selling points are quite hard to find, most things where invented somewhere else. Its more the combination of things and walking the thin line between the text editor and IDE worlds.
Honestly if I could get TFS integration on the level of GIT (for work, although ideally we would migrate to GIT) I would dump VS - it's bloated, when stuff fails you have no clue why or hope of fixing it, VSCode mostly wraps CLI tools so if the default integration fails you can work your way through it, unlike fucking TFS magic VS integrated tracking failing or whatever.
VS is still the only choice for .NET proper, but for .NET Core VSCode is usable enough and improving.
TS integration is the best I've seen, they are the first to support new TS features