The commendations are useless. I only bought 1 piece (my helm) since i never got the drop for it. The pve t2 set is just better, even for pvp. And now that expertise is getting nerfed, this will be even more so true.
So now, you get useless Centurion commendations more frequently, and useful pvp gear less frequently. It might be better just to go for your t2 pve gear and grind valor in Ilum until 60, and then try to get the Champion set.