No drawbacks. sp_configure With no parameters, just shows you the existing settings in SQL Server and if it is active or not (Runnable column).
Passing parameters tp sp_configure changes the settings, well, sort of. The settings are not active until reconfigure is run. You can run both of these as much as you want and it shouldn't be a problem.
The only side effect, is not in running the statements to perform the reconfiguration over and over. But changing a value is changing the way SQL Server operates, and this could be a problem if you change to settings which are not good in your environment. Therefore, you should always test on another system before reconfiguring settings. Also, it is wise to research each setting you intend to change and don't just try them, especially on a production system.