The upgrade to ACS 3.5 will be a little bit of work, so make sure you devote some time to it.
I'm on Oracle ACS 3.4.10 here, and I'm in the process of upgrading to Postgres OpenACS 5.0. It funny, a lot of people seem to have come out of the wordwork recently, and are working on this.
It's not an easy thing to do. But a lot of it depends on the packages that you're using.
How committed to doing this are you? It's a lot of work, although being on a live code base will be a big improvement, and getting rid of the Oracle license fees may pay for it if you switch to Postgres at the same time.
Is there any information available about how Sloan upgraded to OpenACS? If they had upgrade scripts and so on, I would kill to see them.
I have a page up on the admittedly crude way I'm doing it. If I could go back and do it again, I would do it *completely* differently. Oh well, it should work: http://rubick.com:8002/openacs/acs_to_openacs
