I'm not a missionary either, but in 2008 I went with team to Niger, to minister to missionaries. We led a retreat where missionaries come together every 2 years; for many it is the only time they see other missionaries.
I am not qualified to talk about accomplishments; however, I would like to mention one of the things that struck me. People from our home church criticized us for spending so much money on travel, when there is such a need for money in Niger. The wife of the house who hosted us gave a beautiful, tear-filled response, to this effect (not an exact quote): Money is not the greatest need here. You came and showed love, and supported us! You spent time with us. you hugged us, prayed with us, and will take a part of us home with you. A part of you will stay here. This is what it really takes to keep us going, to be able to continue the work we love but that can be exhausting.