I have not bothered to download Dim pro thinking it's just for synthetic sounds.
I'm old school so I'm interested in "real" instrument sounds. IOW strings, keys, horns etc rather than synthetics.
Which of these would be better? Other ideas?
Thanks guys.
Glenn

I have Platinum BTW

Dimension Pro is the one you want to download, it has quite a few "real" instrument sounds.

Thanks Steve.

Dim Pro.  It is the emulation synth in the Cake stable and you have it for free.
 
Rapt pro has all of DimP's samples (I believe) plus Rapt's and more.  But it ain't free.

Thanks AT
I'm installing as I type. Now to refresh how to set it up with my keyboard. lol, I'll review some vids on midi setup.
IOW attach dusty USB keyboard, boot sonar, find keyboard in preferences, install DP from synth rack etc. if I recall

Plug the keyboard into the PC then start SONAR and add the keyboard in Preferences > MIDI > Devices "Inputs."
 
When adding DPro to the synth rack, using the "Insert Soft Synth Options" dialog, select either a Simple Instrument Track or "MIDI Source" and "First Synth Audio Output" and DPro will be inserted into the project with the appropriate track(s). Select the keyboard in the instrument/MIDI track input drop down and enable input echo.
 
Then load a program into DPro by clicking the entry at the top of the UI which says "Empty Program." The keyboard should play the program.

Well described, thanks Steve.
I'm in and good to go.

I also wonder, if I get Dim Pro and Rapture classic with SPlat, what's the point of buying Rapture Pro? Does it have better sounds, different sound engine? Or is it just a newer GUI and better user experience? The same question goes for buying ZETA2 while having zeta classic - is it worth it?
 

Both RPro and Z3TA+2 have different UIs, additional content and demos
http://www.cakewalk.com/Products/Rapture/Try-Rapture 
http://www.cakewalk.com/Products/Z3TA/Web-Trial