For a few years now, I've been doing all of my drum practice pad work on two pads at a time. This opens up a whole new world of practice away from the drum set. By simply using two different kinds practice pads, different sounds are created. This allows the brain to better adapt to the phrasing that each motion produces. In other words, you train your mind to hear the sounds that are possible with the use of any pattern you desire to play. It is easy to layer ostinatos for grooves, or to simply take a paradiddle and split it between the pads.
Although I do not maintain many rudiments as part of my playing vocabulary, I have personally benefited greatly from practicing the ostinato patterns on two separate practice pads. Claus Hessler's book with Dom Famularo - "Open Handed Playing Volume 1" - contains several sections which require coordination with the hands before the feet are inserted. These kinds of exercises lend themselves very well to the two-pad practice work.