I've only seen the last few minutes of the game (Cavs) but it seemed Lamarcus was doing a better job defensively, rotating and protecting the paint.
JJ Hickson gives us very important production but he is what he is - he doesn't pass and doesn't play good defense, especially not Center-type defense. I've seen a quote from Lamarcus saying we miss a big man protecting the rim, I don't know if he has it in him to be that man but it seems like he is at least trying.