Pros
Connection with the community of people from other parts of the world who have sought refuge in and are now contributing to the United States. Knowing that what you do is helping them to help themselves and their families start over. Also, connect with other interesting and talented people - IRC staff and other volunteers. In my case, what I also love about it is getting outside and literally "getting my hands dirty"; I'm a volunteer with the New Roots community gardening Program, which is a key part of the Nutrition and Food Security Program of IRC - Tucson.
Cons
During a time when the US government Executive Branch is actively hostile to refugees, resources for not-for-profit organizations such as the IRC are even more limited than they usually are.