I haven't, but I've been using anti-virus apps since day one. I do have a co-worker that didn't think that a phone would need an anti-virus app. I saw some questionable files on his phone that he downloaded from a place that I would not have with or without AV. He had problems with the phone rebooting, freezing and a ton of other things that it should not do. I know that there were users that reported problems with the Thunderbolt, but I think that his were caused by the user. He had the Thunderbolt replaced more times than I could count, then went to another phone (I think it was the Bionic).
As far as I know, he never used an anti-virus app and continued with the questionable file downloads. Now he wants an iPhone because he thinks that it will be more stable. I have told him that he can't just download everything that he sees on the internet and to treat it like a desktop computer, but I don't think that he is listening to me.