Well if you're looking for a single published article with all of their results, there isn't one, as far as I know. However, since all of their projections are published, you should be able to look for yourself on a year by year basis.
As I've stated before, because of the randomnesss of the game, it's impossible for any system or for any human to have sustained accuracy better than a certain degree.
You can't take the projections as gospel, but that doesn't mean that they're useless either.
Here's a good synopsis of projections (many systems, not just Fangraphs) from 2005 to 2014:
A graph:
FanGraphs
The first takeaway: there's enough there to show the projections aren't random. On average, teams projected to be bad have been bad, and teams projected to be good have been good. For example, consider the teams projected to win at least 95 games. They've averaged 96 projected wins, and they've averaged 95 actual wins. Now consider the teams projected to win no more than 70 games. They've averaged 68 projected wins, and they've averaged 68 actual wins. Projections mean something. There's both signal and noise.
The noise, though, would be the second takeaway. We observe a linear relationship, but with a lot of points bouncing around. People have found this before, but just to re-state it, for the current record: one standard deviation of the difference between actual wins and projected wins is found here to be 8.7. That's a 17-win window, around a central projection, where a team could end up anywhere and it wouldn't even be the slightest bit strange. I know a 162-game season can feel interminable, but it's really not that long, mathematically. There's room for a lot of unpredictability.