I went in 2002. Mostly my bike was ignored. One guy was impressed. But I saw Beemers, wingers and rice rockets all over. I think these days the only people you'll catch anything from are the posers on Harleys (no, not all Harley riders are posers). Real bikers like Triumphs. They checkbook bikers will scoff. Ignore them.
I had a lot of fun. Saw some good concerts. The black hills are beautiful for riding. I was lucky to have friends in Rapid City to stay with. It was my first year with a bike and I was fortunate to go with people with experience at Sturgis. But if you don't have access to those, you should be okay anyway.