I use both Rodinal and Rodinal Special. The name Rodinal Special is a bit misleading as it has little to do with Rodinal as far as I know. Rodinal Special provides finer grain than Rodinal but the short dev times at 1:15 probably does not appeal to a lot of people.

Unfortunately there is little info on the web for higher dilutions but I worked out my times for use with Acros at 1:30 and like it.