I just saw this post on cakewalks Facebook page "Upgrade to SONAR X2 Producer today and get a huge String library for Dimension Pro for FREE." so, the only bonus that we got for upgrading(and paying) early was the download one day sooner then everyone else?

That's right

Those of us who upgraded to Production Suite in August (to get the free X2 upgrade) also got the free strings...although we really didn't know if we'd qualify for it.  I think it's great that Cakewalk is continuing to let others have it too.

Some may feel that it isn't fair, but...Cakewalk never said that the "early adopters" were the only ones who would receive the strings.  They just said pre-order your upgrade and receive a free download of the strings.

People who did the early adopter thing just assumed they would be the only ones to get it.

Those of us who upgraded to the Production Suite actually paid our $100 before the "early adopters" did.  But we also got rewarded with the upgrade to the full version of Z3TA+2 and the PC4K expander/limiter (which was a part of the Production Suite).

Again, I think it's nice of CW to allow everyone who is upgrading to X2 to get the free strings download.  It's a nice gesture on their part.

Put it this way, you haven't lost anything. 

If you read the presale offer which is still in the forum stickies, you'll see that the only special attached to preordering was in connection with getting the download a day earlier.
The free download of the DimPro strings was for anyone who ordered before the official release or upgrading.

http://forum.cakewalk.com/tm.aspx?m=2643918

I had 8.5 producer, I paid "Upgrade to X1 and get X2 for free" for $99.
From 8.5 producer,  some bought X1 for $99 when released and now paid $99 for X2 . 

X1+x2=99
X1+x2=198