So far this year, I have been asked to be an assessor for proposals submitted to three different international funding schemes, with the value of the proposals ranging from $0.5M to $10M. I acceded to the first two requests (one of which has me assessing 7 proposals, the second only one proposal) because I thought it would be useful experience to see how proposals are assessed, in case it brought insights that would be useful next time I submit a proposal of my own. The time commitment is starting to become an issue, though, and starting to clash with my other commitments, so I am hesitating about the third.
So: apart from the small honorarium that some of these schemes pay assessors, is there anything in it for me? Is assessing grant proposals simply seen as part of one's academic community service, to be performed as a good citizen like reviewing papers, or is it seen as a measure of esteem that is therefore worthy of putting on a CV?