It's always a good idea to test patches before you roll them out. This is critical for servers, but it's also important for clients too. But because of the flood of patches admins typically have to deal with each month, client patch testing often gets a back seat to more mission-critical server patch testing.
There's an easy solution though: enroll your most tech-savvy users into an internal beta program and roll client patches out to these users first. Then if something breaks, the users themselves may be able to help you diagnose the problem and find a workaround without having your Help Desk flooded with complaints. Such an approach is called a staggered patch rollout where you first release the patch to advanced users who are used to to pain of troubleshooting desktop computer problems, and only after they've tested things and nothing crops up can you roll it out to the vast majority of users in your company.