Loading time is pretty rough, but it seems responsive enough after the initial load. Probably as fast or faster than downloading and installing GHC locally.
I would assume that in the near future one can preload, cache, update selected WASM packages. I also imagine that sooner than that we can preload open models in the browser to run the natively instead of only invoking third parties (e.g. window.ai in the DOM)
For comparison: the homepage of cnn.com right now is 33.37MB on my machine. 16.82MB of which is JavaScript.