This is built on swc, and they compare themselves to vite, which is built on esbuild. So the answer to your question is that they claim to be roughly twice as fast as esbuild (-based bundlers) in the benchmark in this article.
I'm not entirely sure if we can really tell anything about esbuild from that comparison, as vite's production build time is 1300ms (which uses rollup), but dev startup time 1100 (uses esbuild to prebundle). It seems like vite itself has overhead.
