I've been a user of StarOffice, and OpenOffice for a while. OpenOffice was forked to create LibreOffice a little over a year ago, and I've been using it on my Ubuntu workstation for a while. I recently dumped OpenOffice on my Mac in favor of LibreOffice and though I'd poke around to see if anything was different.
To my surprise, I was able to get the OpenOffice base application to connect to my local MySQL server instance rather easily. I had tried this years ago, and ran into a few bumps which caused me to give up at the time.
This time it was very simple. Give it the hostname, database name, username and password, and I was in.
After I was in I tried creating a couple queries, and forms and found it very easy. The first thing to catch my eye was the visual query builder. One thing I miss from my MS Access / SQL Enterprise Manager / SQL Management Studio days was the visual query builder. Writing pure SQL does get you a faster query, but I always liked to proto-type my queries via the visual query builder first. LibreOffice base gives me this functionality with ANY JDBC or ODBC database I can connect to.
That said, it appears that OpenOffice can now fully supplant the feature set that power users need from Microsoft Office Professional. I know the database app has been there for a while, but now it appears to be mature enough to use as a full fledged MS Access Replacement.