Randomness is sometimes underrated by people in just coming into the world of synthesis, but it is extremely important to make stuff interesting it really adds a little spice to synthesis...
Sapel is a dual tamed random source from Frap Tools.
More info at Frap Tools
Revisions that turned synths into brand new machines
Developments for Korg's instrument have been slow but promising.
Older Music Machines & the People Who Still Use Them