Don, for smfs, you need to insert the voicetron to specific track that provides the harmony (track 5 in case of Tunes 1000 smfs) and save the smf. In PA900, you need to use registration to set the harmonization type with the smf as you know. So imo it's easier to do that in MJPro. With style playing, you can setup the voicetron to trigger on different variations and save it as registration. I found this versatile, however it still buggy as it's not consistent in memorizing the voicetron setup. Sometimes it works, sometimes not.
The PA has many harmony presets in style playing while in MJPro it has only one (3 part voice). I'm hoping Ketron will add harmony types. Without tweaking, I found the MJPro has more punch in vocal processing. MJPro has virtual switch (touch screen) to turn on/off the effects/harmony while the PA has physical switch, so it's just a matter of getting used to. Hope this helps.