Hi
yes, we are running on Oracle (just moved to 12c), but we haven't actually upgraded our product to a recent OpenACS version. What we have done is:
upgraded database from 11g to 12c
switched from Linux to Windows 2012
switched from AOLserver to Naviserver
The job to upgrade to latest OpenACS is still on our list, but we have too long a list of client demands to be able to fit it in at the moment. It looks like a huge task, as there has been quite a bit of customisation to the core made over the years.
I did look into running the latest OpenACS on Oracle 12c (on Windows) and reported any issues to Gustaf, which are all now patched on head.
I'm happy to help out or answer any other questions you may have.
Brian
