I have 3 DUI's and I always disclose them. All misdemeanors, between 1997-1999. They have not prevented me from passing background checks with employers. Strangely, they did prevent me from enlisting in the U.S. Army in 2000 which I could not understand.
Maybe things are different now. I never even bothered to get them expunged but that might help. It took several years for my car insurance to be affordable again, I do know that.