Reader X install

I have read discussions about this but nothing concise.

Here is my dilemma, I am wanting to configure Reader X through GPO, thats not an issue since I can install it with Acrobat X.  Where the issue comes is that all my Acrobat users are not on Acrobat X, some are on earlier versions.  Since Reader X can co-exist with Acrobat X, can it exist on the same machine with earlier versions of Acrobat?  Do both versions need to be 'X' or better for this to happen?

Michael