>> How does it compare to the ports tree and portupgrade tool?
If you are comparing rpmfind vs. apt-get, note, both install software from precompiled binary, then that makes a little sense. ports system in *BSDs installs software by building from source, thus not compariable.
>> switched over to Openbsd, and then free
Since you have already done that, why bother to ask this question? You should know how ports mechanism works.