Seriously, there is only one thing Ronaldo does better (or is doing better currently) than Messi: His drive, which converts into his high work rate, him running tirelessly whenever RM is in offense. It is highly commendable, and football fans appreciate that. Other than that, not so much.
Let's face it, people are saying Messi has been bad, worse than Ronaldo etc. mostly because he was not able to change the outcome of this gloomy and disappointing season by himself. Being the best player we have, Messi shoulders a lot of expectations and responsibilities, both realistic and not. When we are having a trophy-less season, the worst season in many years, people naturally are placing a lot of the blame on Messi. The focus has been centered on his perceived laziness, i.e. his lack of workrate, effort, movement etc., which I completely understand, actually it is a sentiment that I share. However, allow me to play devil's advocate and ask this question: If we had beaten Atletico to advance to the CL semi-finals, and if the La Liga title was still within our reach, with everything else being equal and not changed (meaning Messi is still being "lazy" but scores often like he does), and if RM had been eliminated from the CL, would people be saying that Ronaldo is a lot better than Messi these days?
Again, other than running tirelessly and a much higher workrate, I don't see how Ronaldo is doing better than Messi. They are both scoring a lot of goals. Both had poor games where they scored but nothing much other than that, and Ronaldo more often than Messi in this regard.
If some of those same scoring attempts from Messi and our team that have been blocked or saved had converted into goals, we probably would be having a different discussion right now. Sometimes it is down to luck and accidental factors. If only that shot went in. If Neymar, Pedro or Alexis had carried us through CL semi-finals, if we are still in the race, and if Messi scores some tap-ins or easy goals, would people be calling Messi better than Ronaldo?
I guess what I am trying to say is, there is really not much difference between the performance of Messi and Ronaldo lately. The fact that RM had advanced while we got eliminated, and RM is doing much better than us result-wise had a lot to do with people's assessment that Ronaldo is doing much better than Messi at the moment.