Actually I thought the harmonizer in the 740 was pretty good. The mic processing in it is somewhat limited though.
The harmonizer IS much better in the 9000. With OS 2 it has more parts and it has more options. You can easily assign and save parameters and settings to registration memories. It works well in Vocoder mode, Chord mode and Song mode.
Speaking again of the 740, it wasn't too long ago that I paid more money for a less capable harmonizer than the entire cost of the 740!
With the 9000, you get separate 3-band e.q. for the mic, a compressor, dedicated DSPs, and extensive editing capabilities.
Hope this helps.
Don