The lab I work for (http://lasp.colorado.edu/) has an instrument on board (MASCS). I worked on a 3D visualization tool for the data it produced.
As far as I know, it accomplished all its goals (and more!). Many of the findings, especially the ice in the polar craters, were completely unexpected, and that's the most exciting part of doing science!
In all fairness, that's the most exciting thing for experimentalists. For theoreticians, it's a variation on the same thing, coming up with a theory that explains phenomena beyond what they were developing it for, e.g. Einstein's single greatest personal experience was when he discovered his general relativity explained an anomaly of Mercury's orbit.
Congrats, it must feel awesome to be a part something like this and sad to see come to an end.
May I ask what parts of the project were you working on at the time?
Also, I read about MESSENGER's mission here:
https://solarsystem.nasa.gov/missions/profile.cfm?Sort=Targe...
Did it accomplish all the missions?