Gentoo packages, by virtue of use flags, do seem like they'd take more effort to build and maintain, but I don't know enough about gentoo packaging as I'd like to :p
I have packaged for both Debian and Gentoo; packaging for Gentoo is way easier and more fun, one reason being that (simplified) you're dealing with a single Bash file rather than a magic Makefile and things split into 20+ small files. The difference is huge.