The truth is, we have both songs on our songlist but don't play them much. Mustang Sally gets pulled out when we're playing for old folks---when we're at a wedding or some other gig when we're suddenly faced with a bunch of people in their 60s. Sweet Home gets pulled out on request or if it's a particularly redneck crowd.
I hear you about playing the same songs as when I was younger. I had a particularly eerie feeling creep over me the other night when I was playing "You Give Love A Bad Name" and this pretty young thing was writhing around near the front of the stage and singing along, and I got to thinking..."wasn't I in this exact same position looking at your mother do the exact same thing 25 years ago?"