The definition of "sort" that I'm finding in the context we're talking about is:
the act of separating things and putting them in a particular order : the act of sorting things[1]. The same source gives a further definition as "an instance of sorting <a numeric sort of a data file>." Perhaps -ation adds some meaning, but I don't see how it wouldn't already be present in the context of any hypothetical sentence.
The action or process of the act of sorting seems redundant.
My own bias is certainly towards brevity in most cases where context gives a clear meaning. I should clarify that -ation seems unnecessary where the noun it extends:
(a) already describes a process.
(b) is in common use describing a process.
The suffix seems more useful where it explicitly turns a verb into a noun where there was no suitable noun in common use, or where any existing nouns derived from the same root do not refer to a process. This is the ignored distinction my roommate's offhand comment likely implied.
The problem appears to be that American English simply no longer sticks to the formal meaning added by the suffix. Reserve/reservation and preserve/preservation are used interchangeably to refer to large plots of land left to nature. But making a reservation at a hotel is the process of reserving a room.
I guess this ambiguity is what we get for speaking a language without central authority. I'll take it over ivory tower language academies decrying use of "le weekend..." ;)
[1]: http://www.merriam-webster.com/dictionary/sort