Is there any penalty for using a Perl custom search over one created in Python?
Presently the Perl search is simply going out and retrieving a value in an external database, but in the future we will have more streaming type of custom searches.
Depending on the functions and libraries used for the Custom Command / Action, you might see better performance with python over perl. Only real way to confirm that would be to test using both though...
Typically python is more performant though.