If I used the term "Toon" rather than PC, what would you say? What arguments would you use for or against it?
Thus far, one of the more convincing arguments I've heard is that using lingo from a different type of game (in this case, MMOs) could cause confusion; however, this particular word doesn't seem all that egregious—most people, even having not played an MMO, could pick up from the surrounding context that "Toon"=PC.
Honestly I have no real arguments against it. Tabletop lingo (PC, character, etc.) was used since a while ago in most digital RPGs - both single and multiplayer - and now the digital lingo is making its way back to tabletop. The same could be said about calling low level enemies "mobs".Cross-pollination, feedback influences, whatever you want to call it.
I'm more concerned about talking about PCs/toons only as tanks, DPS, healbots and such, limiting the tabletop experience in equivalents from the digital framework and discarding or not taking in consideration anything else (social interaction, investigation) that doesn't quite compare to combat proficiency.
As in many ways pen&paper RPGs are more varied in mechanics and inner working than the most common MMO games, I find that this kind of equivalences tend to... castrate what could (and should) be a more complex and/or complete gaming experience.
But that's just me.