In the US, people will resort to fisticuffs, over variants of Spanish. I usually translate into Castilian Spanish, because that seems to be the equivalent of "Vanilla" Spanish. No one is really happy (except the Spaniards), but I'm not accused of favoritism.
For what it’s worth, Castilian sounds very odd to American ears. For a good time you can ask «¿en castellano?» and be met with either a blank stare or laughter.
In the US, people will resort to fisticuffs, over variants of Spanish. I usually translate into Castilian Spanish, because that seems to be the equivalent of "Vanilla" Spanish. No one is really happy (except the Spaniards), but I'm not accused of favoritism.