Hi,
you are right [:)]
The Sample Content of the SE DVD Collection and the SE Download Collection is the same.
The Download Collection has a higher price tag if you purchase all collections, as it comes with 1 license for each section (which also gives you the freedom to distribute your Special Edition on different computers, if you like).
VERY IMPORTANT: You have to stay with either the DVD Collection or the Download Collection when you want to upgrade, so you cannot mix the SE Download Collections with the SE DVD Collection.
This overview illustrates the possible upgrade paths.
The choice is up to you, but here´s my personal advice
If you are planning on getting all sections of the Special Editions on the long run, you will be better off to get the DVD Collection.
If you are interested to get, e.g., "just" the SE Strings, stick to the Download Collections.
A little "warning" [;)]: The quality and playability of the Vienna Instruments is quite addictive, so it really makes sense to think this over!
Hope that helps!
Best,
Paul