Some places I've stumbled:
- I couldn't get a clear bell from the INIT patch until I turned off formant shaping (which is active even at the zero setting).
- The classic DX7 basses use a modulating ratio of 0.5, but Aparillo's ratio can't be set lower than 1.
- Operator I and II share a single amp envelope, so the operator that produces a transient keeps producing sound after the "transient" has passed. You can use the mod envelope to move the operator slider all the way to I or II, but then you've used up both envelopes.