scook
Not gonna directly plug the Minimoog Tribute Expansion Pack? That and Muz3um for Rapture (available from patcharena.com) covers a lot of vintage sound. My biggest gripe is the Rapture screen has not scaled to accommodate my failing eyesight.

Thank you for plugging it for me...but since you opened the door, there's also the Electronic Guitars expansion pack, and a video demo of it on YouTube
 
The fact that I came up with two expansion packs tells you something right there about how much I like Rapture. I did them for myself; I wasn't planning on offering them for sale, but the Bakers convinced me otherwise.
 

There was a dx version of VSamlpler included with Sonar 3 and an upgrade that included a vst version that I still have but not used in a while. One of the best synth samplers out. Especially regarding use of and conversion between differing formats.

Yeah, too bad VSampler is in the state it is in. Could use an update. Did like that one but had to give it up after moving to 64bit. Picked up Tassman4 based on the version included with SONAR.

n13L5
Its just if some particular sound attracts me and seems to fit the arrangement, and if the software is streamlined and somewhat quick to use.

Before this one does run off the rails, I want to clarify something... there are two different things here with synths...

1. Performing the texture modeling by tweaking the osicillators, setting LFO's, etc. This alone can take many hours to learn and understand. A quick "reality check" for this is open Z3TA+, right click program->Initialize... then "create" the sound you have in your head (this is actually a very humbling experience).
2. Taking default patches from synths that are close to what you want, and knowing "just enough" of #1 to tweak it to your liking.

   I think most folks (including me) fall into #2... they have a sound in their head and want to get it into recording as quickly as possible. Understanding enough of #1 will allow you to tweak things quickly without having to "create from scratch." All synths operate on the same pretext, tailoring oscillators, so in essence a lot of "this versus that" are niceties between different synths.
 
   Here is a link I dug up long ago of a 40 min Z3TA+ 2 tutorial (http://www.youtube.com/watch?v=ovre1jS-I0A&feature=youtu.be ), the "concepts" apply to all synths, just the UI is different. It is worth taking a look at (or something similar), to make #2 above work for you.

Although I think Rapture is underrated, if I had to choose just one, it would have to be Zeta. I usually don't compare va synths to romplers because they serve such different purposes. I will say that Zeta stacks up better against thirdy party comparable synths than dim pro does. I like dim pro but, it takes a little more than competition to sit well in mix for me. With that said there are outstanding sounds and I do like that it is not the same overused Nexus sounds you hear in pop music

Dimension Pro might be the most used synth included with any version of Sonar I've owned.  Rapture would be the coolest.

Rapture and DimPro are much alike, but have different soundsets.  Rapture is more "synthy" for a lack of better words, while DimPro is more of a sampler.  It comes w/ 7 gigs or so of content, while Rapture is much smaller but includes a lot of single wave forms.  Both come w/ plenty of presets, tho they cover different territory.  IF you are looking for acoustic emulations, 1st stop is DimPro, tho the Dimension folder has plenty of spacey, developing sounds.  Synths, Rapture, esp. with all its step sequencers.
 
Z3TA and Z3TA 2 are virtual analog (VA) synths.  Again, if you are looking for synths, it is a good place to shop.  Lots of arps, bass etc.  Compared to Rapture and DimPro, it is a thicker sound, more analogish.  A lot of dance producers use it.  The other two synths cut through a mix nicely, even when doing analog waves.
 
All have their charms and champions here.  I tend to use all three, plus Kontakt, plus Alchemy.
 
@

Wow. That's revelations. I didn't give rapture enough credit.

n13L5
Thanks for the input...
 
I'm not sure what you mean by 'too much of an open door' in regards to Z3TA 1
What does VA stand for?
 
I'm not really focused on whether something is the 'current style' or modern or old or anything, Its just if some particular sound attracts me and seems to fit the arrangement, and if the software is streamlined and somewhat quick to use.

I just meant that you asked which one would replace with Z3TA+ 2. The most obvious answer is Z3TA+ 1 as the second is basically an updated version of the first. VA is Virtual Analog, which describes most of the way Z3TA+ works (subtractive synthesis). It's not really useful to pit it against a sample playing synthesizer like Dimension Pro, so I meant the VA comment to place it in a category of similar synths, like Massive, U-HE Diva, etc.
I don't know what kinds of sounds you're looking for, if it's bread and butter sounds including acoustics you shouldn't be looking at Z3TA+ at all, 1 nor 2, but at sample playing stuff like Dimension Pro or some NI Kontakt bundle. If it's more vintage style analog sounds you like, you might consider getting a pack from Arturia or Korg, both of which have some great emulation of classics. I have OP-X Pro II myself, in that last category, and I like it a lot. If you're more into modern synth sounds, Z3TA+ is a competitor, together with Massive and Sylenth.
 
Just to show there are many needs and flavors. I couldn't have just one synth myself.

AT
Rapture and DimPro are much alike, but have different soundsets...

I often use DimPro samples in Rapture.  Best of both worlds.