https://shop.presonus.com.../software/notion-prods

Something wrong with pricing, as all upgrades cost the same as ... the full version.

Not on my end..they show correctly, but I'm logged in...

That's what I did wrong! Stooooopid.

Yeah, have to be logged in... Still, can't say I'm happy about what I'm seeing...
 
I own both Studio One 3 and Notion 5.  Here I was thinking they were already tightly integrated, and now I learn I need Notion 6 for them to be really tightly integrated!

I've uninstalled S1v3, but still use Notion 5, so I picked this up. Sloooooow download. All of the sound libraries have been updated, so they need to be downloaded as well. Six bundles, each around 1-1.5 GB. Also slooooooow. I d/l'd the S1v3 v3.3.0 update as well, but don't plan to install it...at the moment, at least.

John, you're speaking of the included sounds, correct?  Not the expansion pack?  (The one that costs $300).

Correct.
 
There appears to be a large number of new instruments that are grayed out. That must be the expansion pack you mention. The six bundled instrument installers are the same file names as in v5, but they are different, and need to be redownloaded.
 
I totally uninstalled v5 before installing v6, including manually deleting some remaining directories and files. v6 came up fine and ran an existing score no problemo. Haven't checked anything else yet.
 
I bought the v5 expansion pack and am redownloading the individual .prox files now. These should still work with v6. I'll update this post once I get them d/l'd and installed.
 
Good news on one front, though. The Harpsichord instrument now shows up! Never did in v5!

Yep, these ones are newly included: Notion Harpsichord, and Lakeside Pipe Organ and Micro Choir from Soundiron

OK, this was weird. I downloaded all of the expansion .PROX files and placed them in the Notion 6 | Sounds | Expansion directory, but all showed up grayed out. So I double-clicked on each expansion prox, but was told it was already installed. ???
 
Solution?
 
Notion needs to copy the PROX files to the Expansion folder itself. I moved all of the expansion files back to my download folder and double-clicked on each one in turn (if Notion isn't loaded, installing the first prox file will load it; leave it loaded). Notion copied the prox file to the Expansion folder and did whatever to let Notion know that the sounds were there. Now I have 100% of available Notion sounds actually available to me!
 
When doing this, I don't think it's then necessary to do a Help | Software Activation | Receive Licenses. Well, I didn't.
 
Looking forward to trying the new, very cool looking, drum notation entry feature!