Currently I use CSIDL_COMMON_DOCUMENTS for my data and ini files. I chose
that because of networking issues as I understand that is always available
across a network. That is now not relevant.

I am thinking of using APPDATA but not quite sure if I should use the
personal (user specific) one or not.

You see sometimes my clients share the machine with their wife say and their
wife might login under their user account. The client then comes along and
would not find their data. So I am inclined towards installing the data
independent of the user so presumably comon_appdata.

Would that make sense?

John