This is a simple OF/OF swap. Gerut is about 18 months older than Dubois and has more major league experience.
In terms of Gerut, the dangerous trend is the alarming decline in power:
Perhaps I'm higher on Jason Dubois than most, but I definitely think that the Cubs gave up on him too soon. In 152 PAs, Dubois had a line of .239/.289/.472. While the OBP is incredibly low, here's an optimistic spin - if 6 bloops or line drives had fallen in, Dubois's line is .282/.329/.514, which, all of a sudden, is fantastic. (Of course, if 6 fewer balls had fallen in, his line is .197/.250/.430).
The lesson of all of this is that the isolated power is there, meaning that there could be a very solid player underneath the impatience; he hit .316/.389/.630 in AAA last year and .269/.367/.458 the year before.
I think that Cleveland got a very good deal here and that Dubois, at his peak, will be a very dangerous power bat towards the bottom of a lineup. Gerut? Wasn't starting for the Indians, and Dubois is a much better power threat and a much better 4th OF at this point.