Thanks for trying it out! Yes, language support is still being actively worked on, and unfortunately the syntax highlighting isn't quite to parity (yet). If you are able to log an issue with the specific case you are seeing, that would be very helpful.
It's definitely a goal of the project to be on-par with other IDEs in terms of language support, but unfortunately we aren't there yet.
Author here - Thanks for trying it out I had the same issue in setting up omni-completion for JavaScript and TypeScript, and wanted to save others that pain. It's crazy how much time I spent trying to get YCM to work on Windows with TypeScript... But I'm really glad it worked out of the box for you!
Author here - thanks for the kind words! Yes, your comment hits the nail on the head and echoes my thoughts exactly. Electron happens to be a great way to test out some of the thoughts and I ideas in an economical way - especially since my time to work on Oni is limited at the moment.
And I think the fat headroom for improvements is important to call out - when people talk about "Electron Bloat", they usually refer to one of 5 things:
1) Footprint (space on disk)
2) Memory usage
3) CPU usage (corresponding to battery life)
4) Responsiveness (esp typing latency)
5) Startup time
As you mentioned, across the board, there's a bunch of room for improvements - especially with tech like WebAssembly on the horizon! #1 and #2 are the hardest, because Electron will always have a fixed overhead - but when comparing to an IDE like Visual Studio, it's not over the top.
For my workflow, #4, #5, and #3 are most important, and Oni still has plenty of low-hanging fruit to tackle for each of those. If I find there is a blocker to getting to acceptable typing latency and startup time, I'd consider making a switch (potentially to a react-native-on -desktop solution), but I'm optimistic that with WebAssembly, React 16, Chrome 61, along with optimizations on the Oni side, there's still plenty of opportunity to improve performance.
Problem: It's hard to configure Vim/Neovim to work like an IDE, and the terminal UI isn't the same as something like Atom, Sublime, or VSCode. Vim plugins for those editors never quite hit the sweet spot for me in terms of using the muscle memory I've built up.
Project: Oni (https://github.com/extr0py/oni), a Neovim front-end with out-of-the-box IDE functionality (right now, supports JavaScript & TypeScript).