Forum OpenACS Q&A: Response to Planning a migration from ACS 3.4.x to OpenACS?
Hopefully Malte's fixed those problems?
Also I don't think it's exactly true that you can just choose not to load the education stuff and then have a vanilla ACS 3.4. It's been a couple of months since I worked on the code base for Sloan, but IIRC there were some hacks to things like registration that changes stuff.
A cleaned-up ACES code base would be fine with me (and, again, maybe Malte et al have done the necessary work) but the tarball as it exists at aD has problems.