Ok, I also watch La Liga so I'll put my two-cents in here. Ramos at RB is a bit better than Caceres right now but not the world-beater people make him out to be. His positioning is about the same, not so great. Always has to run back and hack someone down if they get slightly past him. Picks up way to many cards for my liking too. He's good in the air though and likes to get forward even if he's not that good at it.
Caceres on the other hand does make rash decisions at times but he is being played out of position, and it's simply not the same defending as a CB and a RB. Two very different roles that require different things. I personally think he just needs a while to learn the ins and outs of RB since this is the first time he's really played it. Once he familiarizes himself with the role and learns how to choose when's best to push forward then I think we'll see the best of him.