I remember that you previously posted that, because of your marriage with an Argentine, you believe that the permanent residency you are presently seeking would be sufficient.
Unless migraciones starts deporting ALL foreigners, regardless of race (i. e. including Caucasians), you should be just fine.
One advantage of having citizenship might be (based on one of Dr. Rubilar's posts) is that if you are ever charged with a crime you would most likely remain free (at least until the trial is over).
And, if you now have a US passport, you would no longer need a visa to visit Brazil.
I'm not sure if having "citizenship" would make you "immune" from any "hostile" actions by migraciones. I hope Dr. Rubilar will comment about that. I think he previously posted that citizenship granted to a (non-Mercosur) foreigner could be revoked but I'm not sure who would have the power to do so (perhaps by the order of a judge?).
In other words, I hope that having Argentine citizenship could only be revoked if you are convicted of a "real" crime and not by the order (on the whim) of anyone at migraciones.
Based on Dr. Rubilar's posts I have the impression that there is a deliberate effort to purge Argentina of non-Mercosur, non-Caucasian, foreigners, even if they have "legal" residency, so if you're white, you shouldn't be too worried, at least not yet.
As always, i appreciate updated information on this subject and/or corrections to anything in this post.