Pete, they are in the Sandy Springs Plaza shopping center (corner of Roswell Road & Johnson Ferry Road.  It's the long strip mall on the right side as you're going north.  Just renovated.  If you have a GPS, here is their address:
6277 Roswell Road, Sandy Springs, GA 30328
If you know when you'll be there, you might call ahead and reserve a tri-tip.  Their number is:
(404) 236-2414
Don't even think about going through Sandy Springs on a Friday from 11 to 2 and at rush hour any day, although early in the week might not be so bad.  Email me privately and maybe we can work something out to get you a tri-tip.
Rita