i was wondering when parametrics would get its own thread, seeing as it's at least mentioned in half the theory threads already.
i don't have a strong opinion on it, but i feel like it's a lot harder to argue parametrics than it is to argue against it (i.e. it's harder to justify a topical CP than it is to knock it down). so i would never run a topical CP on NEG and i would argue against a topical CP if i was AFF.
in terms of arguments, it makes sense to say that AFF means affirmative side of rez and NEG means negative side of rez. so thus a CP that affirms the resolution is just another reason to vote AFF. but it also makes sense to say that AFF means the affirmative side of the case and NEG means negative side of the case. and then as long as the CP isn't the case it's legit. IMO the rez-centric interpretation is more intuitive than the case-centric one, which is why i think it's easier to argue.
the reason why i'm not personally committed to either side is that i haven't really seen any warrants from either side regarding why i should believe their side. in other words, to the parametrics people: why should i prefer a case-centric interp over a rez-centric one? and to the non-parametrics folk: why should i prefer a rez-centric interp over a case-centric one?