From reading some other posts having 7.51 and 8.0 on the same computer works.
Fine.

No what about the Extra Content DVD from 8.0?

Should I:

1. copy it OVER the existing 7.51 Extra Content?
2. install it to a different path, having both available all the time?
3. join both content versions, and keep identical named  files from 7.51? From 8.0?

I'd prefer option 1.

I personally prefer the content that comes with Vue as it is - for each Vue version I have. My personal and purchased content I have in a separate structure that i use from all Vue versions.

The plus is that you do not waste disk space and you do not have to care about actuality for your personal stuff.

The minus is that the collections are not updated automatically when I change something in the folder structure. Which is not a big thing in my eyes, it takes me something like 20 seconds to reload my personal collection structure manually. And that only when i change the folder structure, new items in an existing folder are detected automatically.

Another minus is that the automatic installers do not work of course. I have to install all content manually. something I prefer anyway because then I KNOW where my content is exactly. And do not have to do searches and guesses where it is.

I do exactly as wabe does, in all details. :-)

My license with E-on won't let me have both 7.5 and 8 installed.

I have just downloaded Vue 8 Infinite. I did not get a link to an "Extra CD Content" for Vue 8. I just assumed it is the same like Vue 7.
After reading this thread I am not sure if there is or is not and Extra CD Content for Vue8 Infinite.
Would somebody please tell me what is correct?

I did download 1.1GB of extra content.

Found the link from e-on site under my account

 the link for extras was already there when I first got vue 8 but I think it was 690 MB now it's 1.1 GB so I am redownloading. I didn't get any notice that it had changed though???
Love esther

Mine was 1.54GB unzipped.