Obama Commutes Sentence of Chelsea Manning

Jeez, can anyone just tell me whether this is the right thing to do or not? 

   It's embarrassing how bad my grasp is of the Manning and Snowden cases. You know how there are just some issues that slip through your fingers and you never quite make a sufficient effort to run them down? (Well...that's me for a lot of issues...but...anyway...) I wish someone would just tell me the answer here. Or at least point me to some of the better things to read. I'm generally sympathetic to whistle-blowers, but have never been inclined to put either Snowden or Manning into that category. My badly-justified conclusion in both cases has tended to be: pretty much guilty. Also, I've forgotten most of what I did once know about these cases.

   (I've also heard it suggested that there is another issue in play: that the government doesn't want to have to deal with the question of a "sex change" for Manning. That doesn't seem like a terribly difficult issue to me, but I'm obviously out of step with the current consensus of the left in this respect. Also, I can't imagine that such a consideration could trump considerations of justice.)