Yes, we're certainly inspired by Kanso.

PgREST was originally designed for a large, in-production Postgres app (i.e. Socialtext), so we can get all the model, validation, view & trigger code in one place, getting the benefits of CouchApps while maintaining the underlying data layer.

For new projects, the main difference is likely familiarity with the toolchain (npm+Pg vs Kanso+CouchDB).