I'm not sure what extra acoustic emulations RaptPro has over DimPro.
I do know all the organs I expected in DimPro were actually thick as thieves in Rapture. That is one aspect of RaptPro that is easy to overlook - having one synth to look though for needed programs instead of two. Oh, shoot, that "Jimmy" organ patch is in Rapt not Dim. It does save time whether you are looking for a specific sound or just browsing. And there is plenty of new content in Rapture Pro that isn't in either DimPro or Rapture. It comes w/ 12 gigs, which is a few gigs more than DimPro if I remember. And it points to other libraries you may have bought. If you can get it cheap right now it is a good investment for the long haul, if you are a synthesis. If not, it might not be worth it. If you are heavy into acoustic emulations for sound tracks etc. you just need to spring for Kontakt and some orch libraries (more of a giant leap than spring, since you'll be spending hundreds of dollars just to get up and running w/ a smaller library than Rapt.
Z3TA 2 does everything that Z3TA + did and has about the same # of extra programs. It is a synth's synth, and if you are looking for an acoustic emulator you are barking up the wrong tree. It has a few synth wave forms, not sample. That being said, it isn't a great analog emulator either, being too cutting rather than round and smooth. And many of the 2000 presets are more dance oriented. However, it has a great mod matrix and I use it like a modular analog synth. Z3TA 2 has a few more of this and that (and lots of new presets) but the outstanding feature for me is syncing the wave controllers to lfos etc. or playing them live. It is kinda like wave-sequencing, in that you are manipulating the raw sound of the wave, rather than the subtraction part of analog synths. Very cool, but I doubt you'll find a lot of acoustic uses for it.
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