official openbsd recommendation to install packages (not ports)?

[boder]

i noticed in the packages and ports section of the openbsd faq, the team recommends NOT to compile packages from ports. they claim that the binaries have been tested more and that ports could cause problems, i was wondering if there is anything more to it, where do these problems come from. i found it interesting to read that recommendation given the enthusiasm about compiling from source from some projects (gentoo, for instance). what exactly is the difference between a binary compiled from source by ports vs binaries from pkg_add? it seems to me that during the compilation process a more customized profile is made for your machine and the packages on it and therefore that would make it stable, anyone know what's wrong with this? thanks.