Most of APT packages' superiority comes less from the packaging format than the entire philosophy surrounding them, most especially in the case of Debian, Debian Policy. Quite simply,
so long as I stay within distro, the quality of Debian packages
greatly exceeds those of RPM packages (long-standing direct, multiple-instance observation of Debian, REHL/Red Hat, CentOS, Fedora, and Suse systems).
Some of the benefit also derives from the packaging format itself. The ability to unpack DEBs using nothing but shell tools (busybox within a Debian system's pre-boot ramfs is sufficient and has been successfully used by me -- Red Hat loses in this instance by using a ramfs shell that's both 1) larger than Debian's dash and 2) doesn't offer interactive use -- it's a scripting-only shell, FML.
Joey Hess at one time had a detailed comparison of various packaging systems. He's pulled it apparently due to political / fanboi bickering, which is a shame. He's author of 'alien', a tool for converting between packaging formats.
But Policy (and fucking enforcing the fucking hell out of it) trumps.
Source: 18 years' use of both distros and many other Linuxen. 30 years' experience on further Unixen.