Messi with his supremacy between 2009 and 2012 is exactly as Joe Frazier who has been on top of boxing for a short period of time (1970-1973), then nothing after that. Ronaldo with his dominance at Manchester (until 2008) and its evolution and explosion at Real Madrid until now is just like Muhammad Ali who was at the top of boxing (Champion) from 1964 to 1967 and regained his title of champion in 1974, defended it 10 times until about 1979-1980.
About the elegance, Messi, small-sized (as Joe Frazier), do not pay attention too much to the elegance and appearances. But Ronaldo, taller (like Muhammad Ali) is too elegant, devotes time for it and love the style.
Given the similarities between the two great players and two great boxers, Ronaldo can say as Muhammad Ali: "Messi is the best of all time next to me."
Also, given the similarities, it is clear that Messi will never reach (be back to) the level of Ronaldo (a problem of fitness and also aging of Xavi and Iniesta, Messi should thank them for all the rest of his life) and that Ronaldo will make his way quietly until a given period of time.