I've always found ORMs to be performance killers. It always worked out better to write the SQL directly. The idea that you should have a one-to-one correspondence between your data objects and your database objects is disastrous unless your data storage is trivial.
The issue of creating a DB wrapper doesn't go away by using an ORM. One of the complaints about ORMs I have, in practice, is people often create another wrapper around it.
I saw that a lot, too. I remember one project using Hibernate where the people involved decided to keep the Hibernate objects "pure" and then had them all wrapped in another object they used to keep information that didn't go into the database.
The whole project must have had 3x the number of classes that the actual complexity required, and keeping it all straight was something of a headache. As was onboarding new people, who always struggled with Hibernate.
