Currently to test if an import is creating/updating records as expected one has to create a separate import file with just the first record or few records in (and remove these from the rest of the import). This is not the same as validating, which only checks for technical errors, such as missing compulsory fields.

Could there be an option in the Import parameters to import only the first x records (which the user could specify) and then stop so these can be checked? If it's really clever, it could then resume from where it stopped.