The numbers so far show that the difference between no compression and Gzip are vast, whereas the difference between Gzip and Brotli are far more modest. This suggests that while the nothing to Gzip gains will be noticeable, the upgrade from Gzip to Brotli might perhaps be less impressive.
Gzip made files 72% smaller than not compressing them at all, but Brotli only saved us an additional 5.7% over that. In terms of FCP, Gzip gave us a 23% improvement when compared to using nothing at all, but Brotli only gained us an extra 3.5% on top of that.
So Brotli is just like spicy gzip.
Still, I’ll take a handful of points by flipping a switch in Cloudflare.