I found Bun to be faster. Monorepo support is a bit kludgy though. Once you know of the workarounds, it's ok. See my comment on https://github.com/oven-sh/bun/issues/5413#issuecomment-1956...

AFAIK, Pnpm monorepos do not follow standard npm. Bun does follow standard npm monorepos.

Pnpm's feature to override dependency versions is nice for legacy projects with many 3rd party dependencies. Not sure if Bun has the same feature. I mostly use it on greenfield projects with dependencies that I control.