i have done a little testing with it (build a db driver, ran some queries).  i also joined the XQJ mailing list and the XQJ bug tracker.  i see that there are definitely bugs open, and seems like the code-owner is working on them. 

i have not checked back in a while on the project (2 weeks now) but i should.

i really like the idea of XQJ as the next replacement for XMLDB.  from reading the eXist mailing lists logs, everything is based on XMLDB which looks to be a dead standard.

i would be really interested to know how other users are thinking of XQJ and what they are doing with it (if anything).  I wanted to start writing production modules on the driver, but then decided to wait a bit and watch the project and see if the bugs were getting fixed in a timely fashion.

good luck,