Which Phase Distortion app should I get?

[Korg Supporter]

I already have FM4, which uses a similar sound synthesis method. I still have some strange interest in Phase Distortion, but FM4 can make similar sounds. Is there any reason to get Phase84 or Casio CZ App? Phase84 is cheaper and seems to have more features, but Casio CZ has direct Audiobus suppport. Which one sounds better? Which one is less buggy? Which one has better MIDI? I also posted a thread about additive synthesis apps on the getting started section of the forum.