Best practice: Install for all users or only current user?
Solution 1:
It really doesn't make any difference. The vast majority of apps you will ever use will install in a different location (root Library, or user Library), but their configuration will always be user specific.
If you never intend to have other users on the system, the only difference will be remembering where something is installed when you go to delete it.
Solution 2:
I recommend using current user for most stuff for the sole reason that if one app, plug-in, library, etc., messes up with your system in any way, creating a new user can help you diagnose the problem.
The more you have contained in your user account, the less the chances that your system might experience account-wide problems.
Other than that, what @jason said, is actually correct.