Reinventing the Wheel
Apparently the latest in a long line of folks reinventing wheels to make apt-get update more efficient is Steve McIntyre. I’ve blogged previously on the topic. I don’t really have much more to say than that; in comparison Steve’s proposal requires fancy downloading, changes to apt-ftparchive and changes to the Packages file format in order to handle removed packages. By requiring you to download the entire stanza for every updated package, it’ll also lose on efficiency in general, although it should gain on efficiency for people who update very infrequently.
Given pdiffs are conceptually more straightforward, can be trivially added to the archive by writing a couple of scripts, and have been successfully implemented in the past, I don’t see the point in reinventing this particular wheel instead of just building it as specced.