Unless Boobie is the second coming of Easley on special teams (which I haven't noticed), I too would look to replace Boobie. We haven't seen enuf of Gilislee, but so far he looks like a good # 3, not a main backup to McCoy, and if, as has been suggested, Karlos is not the answer, then we could likely do with an upgrade. But I'm looking forward to seeing more of him in the next three games.
As for the Miller comparison, just checkout Miller's TD run versus the Giants with Gillislee's TD run vs Philly. Very similar styles it seems to me.