codesmell.org

I found this to be true, especially the bold statement. Unfortunately this is more a JBoss issue than a Hibernate Issue as this problem is very obvious in the SEAM ‘community’ as well.

Open-source projects in general
are a liability but Hibernate specifically has a serious support problem. Unless you pay the organization money you will find their support is terrible. Bug reports and feature requests will get closed with rude remarks. Posts on discussion forums get ignored. General (free) support is very hard to come by.

Anyone considering using Hibernate should realize that 90% of the time it works like a charm, but you waste
days fixing problems with the other 10%. This is how they make their money, as do many other open-source projects, by making the product harder to use and charging for support.

The biggest ease-of-use concern with Hibernate are its exception messages. Sometimes you get misleading error messages that point you in the wrong direction. Other times you get messages that are so vague you have no idea what has gone wrong.
If you file a RFE asking them to improve error reporting you will get a rude remark and the RFE will be closed promptly. Just my 2 cents.