A while back, Andrew at Jimmy Page's Sweater Vest wrote an incredible post that explains why Rod Stewart is someone to be respected. For some reason, I didn't link to it, but the post is timeless, so I'll do so now. Here's some of it, but you should read the whole thing (there's even some stuff about the Advanced Theory, but you can skip over that):
"Despite enjoying many of Stewart's radio hits, I never credited him with having anything to lose, as it were. He's always seemed content to be an amiable buffoon, a cartoon lothario who'd recently settled into a lucrative senescence croaking out second-rate versions of Cole Porter songs. I wished him well but wasn't interested.
Moreover, Rod's pink-satin-blouse period is still fresh in many people's minds, and someone in the comments section of this blog recently noted he was quite upset at Stewart for 'mauling' (his word) a Tom Waits song. I sympathize with these objections."
Having established this, he goes on to deal with a number of issues, including the genius of Every Picture Tells a Story, how best to buy Rod Stewart music, and how Stewart can help you overcome your qualms about embracing blues-rock. It's a must-read for fans of Advancement.