Thanks again for the information. Upon more examination of the differences between Music Creator 6 and Sonar X3 -- namely instruments -- I made some observations.  Not only does Sonar include CSC, TTS-1, and SI Drum Kits, but also SI Bass, Strings and Electric Piano.
 
Unfortunately, it also seems the MC6 SI Drums kit is far bigger than the one in Sonar. MC6 contains 35 programs, but Sonar only offers 18 programs. (See this video at 2:35.) "I know, I know...how many drum kits do I think I need?"
 
So, to prevent obsessive overthinking, I must ask:
1) Am I correct to assume that the SI programs are not different instruments, but different presets of the very same instrument? (If yes, then perhaps a difference in variety won't matter much).
2) Does the SoundCenter selection differ significantly between the two products?
 
I guess I don't want to shoot myself in the foot by losing a bunch of instruments through this upgrade.
 
EDIT: Using my MC6 registration code, I downloaded MC6 Touch for free from the web site! I'm so excited, I didn't know this offer was available.

SONAR includes Session Drummer 3 too.
 
The Studio Instrument Drums video is pretty old, describing the original release (and name) of the product. Pretty sure there is only one version of SI-Drums, my SI-Drums contains 35 programs (I have X1-X3 Producer installed).
 
There is only one Cakewalk Sound Center.
 
If there is any concern about sample and program difference between SONAR and MC6, leave MC6 installed when installing X3. There is so much overlap between Cakewalk products, prior versions and products do not take that much disc space.

scook
SONAR includes Session Drummer 3 too.
 
The Studio Instrument Drums video is pretty old, describing the original release (and name) of the product. Pretty sure there is only one version of SI-Drums, my SI-Drums contains 35 programs (I have X1-X3 Producer installed).

 
Just upgraded to my free MC6 Touch! I love it so far. Immediately spotted some of the added features (take lanes, automation buttons) and visual and functional enhancements (smoother fonts, enhanced textures and panes)
 
You were right about the SI instruments. Those videos I viewed were rather old, as the variety of SI instruments is outstanding! (45 Piano, 35 Drum, 45 String and 60+ Bass...yowza!)
 
I'm so pleased with this upgrade thus far! (Still looking forward to buying Sonar.)
 

So, just wanted to confirm that I can upgrade straight from MC6T to Sonar X3 Studio -- although, on the purchase page, in the Checkout corner, it doesn't specify that exact transition.
 
Also want to confirm that the upgrades are the actual full products for which my previous version needs not be retained.
 
Do Cakewalk products have an activation limit? I am a PC enthusiast and I do rebuild/upgrade my PC occasionally.
 
Last question: disc or download, does it matter? I prefer the download, but I don't want any unforeseen restrictions going that way.
Thanks again for all of your guys' knowledge on these topics... :)

As the registered user of a Cakewalk product, you qualify for the "Upgrade for any registered customer" price.
 
Yes, currently all SONAR upgrades are full retail versions and require no previous version of any product be installed.
 
No activation limits. Install as often as necessary. SONAR uses a simple Serial Number/Registration code for activation.
 
Keep the downloaded installers locally. It is possible to create discs similar to the physical media by expanding the downloaded installers using 7-ZIP and burning on DVD-DL. I keep several copies of all my downloaded installers and a snapshot of my registration page, just in case.

scook
 
Keep the downloaded installers locally. It is possible to create discs similar to the physical media by expanding the downloaded installers using 7-ZIP and burning on DVD-DL. I keep several copies of all my downloaded installers and a snapshot of my registration page, just in case.

Awesome! I feel much better about the options. I'm looking forward to picking up Sonar X3 Studio within the next few days... :)

At the bottom of download installation instruction page are links to tables containing information about the download installers for each version of X3

Make sure to apply the X3e update for your version of X3 http://www.cakewalk.com/Support/kb/reader.aspx/2007013361
 
Also, if you leave MC6, MC6T or have any 3rd party plug-ins on the PC, follow these instructions after installing http://www.cakewalk.com/Support/kb/reader.aspx/2007013315 It won't hurt anything if you do it even if the previous products have been removed. It is a process to clear out the VST inventory from the registry and build it fresh.
 
With X3 both the 32bit and 64bit versions may be installed on the same machine. From quick scan of the feature list, Dreamstation, a very old synth, is the only 32bit plug-ins which cannot be used in the 64bit version. If it were me, I would not bother with the 32bit version of SONAR.

What scook said.
Fwiw, it won't hurt to leave MC6 on your machine. the program itself is very small.
I actually have all of the Cakewalk programs listed in my signature installed on my laptop. I mostly use X3 Studio now, but I keep the others handy for quick reference in case a question pops up.
As to migrating to a new machine, Cakewalk is the absolute easiest to deal with. Your registration info is always available in your account.
Some 3rd party plug-ins are another matter, so keep detailed information about all of those.

RobertB
What scook said.
Fwiw, it won't hurt to leave MC6 on your machine. the program itself is very small.
I actually have all of the Cakewalk programs listed in my signature installed on my laptop. I mostly use X3 Studio now, but I keep the others handy for quick reference in case a question pops up.
 

Agreed. On my XP machine I had SONAR 1XL though SONAR 8.5 Producer. Did not bother with the Pre-SONAR stuff. I bought a new machine almost 2 years ago and it now has SONAR X1 Producer Expanded through X3 Producer. There is a good reason to keep the original MC6 installed, MC6T not so much but won't hurt. There was a significant change in the underlying MS libraries between MC6/X1 and MC6T/X2. Adding touch to MC6T/X2 and newer had the side effect of dropping XP support and some older third party plug-ins don't work with the newer libraries.