What are the pros and cons of using Hibernate in a Java application? Specifically, how does it affect the response time for the user who is for example, updating a zip code in a customer address?

Specifically it can improve performance by affecting the design of your application since you can have long running conversations and optimistic locking which avoid that the user has to "lock the record" while he's on the webpage slowly typing it's zip code and drinking coffee.

Some more details about performance here:
http://community.jboss.org/wiki/Hiberna ... formanceQA