It's not Metol alone, but Metol and a low sulfite concentration that makes Beutler's an acutance developer. D23 contains enough sulfite that it acts as a silver solvent, with the result that it is a fine-grain low acutance developer.
Personally I find the Rodinal grain more "messy" than other developers - not so much coarse as "coarse". Rodinal was originally intended as a fine-grain developer, but at concentrations of around 1:10.
Since it also offers very little speed increase, I find no other big advantages than the longevity of the concentrate. BTW - I love it for glass plate negatives: 5ml Rodinal in 5cl water to develop one 5x7" glass plate or two 9x12cm ones. That works great, and fast!