You can find this option from SQL server 2016.
Use trace flag 4199 on earlier versions of SQL server to utilize the similar feature.
When you apply any hot fixes, cumulative update or service pack, SQL server optimizer would utilise the changes immediately, in case if you enabled the query optimizer fixes. The new patches can result in performance improvement or degrade.
Choose ON or OFF?
It depends on environment. For example if you have UAT environment then apply all the new patches and make sure environment is stable, then proceed to apply the patch on production. In this case you can enable QQF.
If you don’t have testing environment then better OFF the QQF, it may impact (Positive or negative) the optimizer performance because of new update.
In general if you need to maintain the baseline performance better keep the QQF off, if you feel all new new updates may yield better performance then enable QQF.