A developer would like to view page transaction response times.

The request log in AEM records details about requests processed by the AEM instance, including transaction response times. This log is useful for developers when they need to analyze the performance of page requests, including how long each page takes to load. The request log can typically be found in thelogsdirectory of the AEM installation and may be namedrequest.log.

stdout.logtypically contains the standard output of the AEM process and is not specific to request transactions.

audit.logis used to log user actions for auditing purposes and does not include transaction response times.