Pros of having a friend with benefits include the lack of commitment required and the option to date multiple people. Cons include the possibility of ending a friendship and the lack of emotional commitment. A friend with benefits arrangement is convenient, which can be a pro or a con.
The lack of commitment in a friends-with-benefits arrangement allows both parties to fulfill their sexual needs without committing much time or money. This allows them to focus more on other life goals. Since a friends-with-benefits arrangement isn't exclusive to one partner, it also allows both parties to date other people, so each party has more chances to determine likes and dislikes in a partner.
If one party in a friends-with-benefits arrangement has or develops feelings for the other, it often leads to a desire for a real relationship or jealousy issues. In some cases, this can end the friendship. To avoid this issue, both parties should be clear about the arrangement beforehand and neither should have romantic feelings for the other. One or both parties may also end up wanting an emotional connection, which the friends-with-benefits arrangement doesn't provide.
A friends-with-benefits arrangement is convenient for both parties, as they don't need to go on dates and can see each other whenever they want. However, this convenience can be a drawback, as one or both parties may have less incentive to pursue other relationships.