Normally the negative comments I get are from drivers, usually in a pickup truck. Other cyclists are usually a bit nicer to me, though there are the occasional exceptions.

About 5 years ago on a local bike shop ride, there was one guy with a very nice Campy & carbon (forget the brand) $10,000 bike. I, on the other hand, rode an entry level aluminum Sora equiped Trek 1000. You could pretty much just smell the contempt and derision sweating out of his pores. Despite being a pretty friendly bunch of riders, he barely even acknowledged me. I made it a special point to show that it's not always the bike and crushed him everytime we had a chance for a sprint or hill climb.

After about a month of twice a week rides and doing this.....he stopped ignoring me and became friendlier, commenting on how fast he thought I'd be with a higher end bike.

I still have that Trek and put plenty of miles on it.