Re: Why use this ?
Mainly because squid will download the Packages.gz file every time it changes: we only xfer the diffs (rsync). The auto-clean (only if a newer package) feature, fallback backends, and the fact that the cache layout maps 1:1 with the backend(s) (re-export cache via NFS/rsync/ftp) also helps.
That said, if you've already got squid up and running, it might be easier.
This package changed my life!
This code is truly beautiful. The authors are geniuses. My mummy said so.