Hmm I hated the South American maid arc mainly cause of Roberta and co. Most of the action is Black Lagoon is unrealistic but in a fun way, the maids were just plain hax without the atmosphere of characters like the hax charas in for ex hellsing etc. Plus the entire arc could have been labeled BL for reasons other than being in Black Lagoon, if it's gonna be like that at least have some shit go down =P
Were you even paying attention? She's an ex-FARC paramilitary trained international terrorist and essentially bodyguard. I loved the atmosphere of the Roberta arc, the tension was amazing.