It all depends on how it's used. Dat swaps -should- be merely a cosmetic enhancement to visuals and audio (as it is for me). Unfortunately there are loopholes in which it can be used to create an unfair advantage over others, ie: the treasure chest/coffer trick, replacing names for placeholders, removing crowded mobs in a NM spawn point etc.
Edit: The downside is, it's client side only and exists only on your hard drive. Even a process checker wouldn't tell SE anything on whether or not you replaced bits of data.