The most heard gripe was the concurrent access to the database file but I think that was solved by backing the forms by accessing anything over odbc.
It looked terrible but also was highly functional.
It was for school, and I recently found the write up and was surprised how well the system worked.
Ever since I've marvelled at how easy it was to build something highly functional that could incorporate complex business logic, and wished there was a more modern equivalent.
I've not seen anything as easy to use as the Access visual query builder and drag-n-drop report builder thing.