TypeScript 7.0 Beta makes performance the feature, and I do not think that is a small thing. The TypeScript team says the new Go-based compiler is often around 10 times faster than TypeScript 6.0. It can run side by side through @typescript/native-preview and the tsgo entry point, which makes it much easier to test without turning the whole workflow upside down.
For large TypeScript codebases, this matters more than a neat language feature. When TypeScript is slow, you feel it everywhere: editor feedback, CI, refactors, builds, and the general confidence that the project is keeping up with you. Performance is not just a benchmark. It changes whether the tool feels like help or friction.
I would not blindly replace everything in production on day one, but I would absolutely try it. Run tsgo locally, run it in CI as a non-blocking check, compare the output, and find the tooling that still assumes the old JavaScript implementation. That is the boring path, but it is the right one.
This is one of the more interesting developer tooling changes this year because it attacks the daily wait. Not the flashy part of the work, but the part you feel every time you save a file or wait for an editor to catch up. If the beta holds up in real projects, performance really is the feature.