I've never tried Avantis, but I have tried the Fetherlite which, according to the Durex website, is the thinnest condom they offer. They still suck. This quote from the article sums up my feelings on the issue:
To me, condoms ruin the only thing which they are for: sex. And you expect people to use something which only gives negative associations during the most irrational time of their day. I do things during sex that I wouldn't even consider in any other context, that's a pretty good time to make some bad decisions. If a condom was invented that didn't noticeably diminish feeling, didn't cause me physical pain, and didn't break at the drop of a hat, that would be a revolution for me. You can't tell people to buy the brand that works for them when none of them do. Maybe condoms don't bother you, and that's good for you, but you can't argue with the insane statistics presented in this article: 45 percent of men and 63 percent of women who’d most recently had sex with a “new acquaintance” hadn’t used a condom. 75 percent of women who weren’t using a back-up birth control method reported not using a condom the last time they’d had sex. Adults who’d had anal sex in the past year—the highest-risk sexual act with regard to HIV transmission—said they’d used condoms only 20 percent of the time. People hate condoms. Something should be done.“The most enthusiastic endorsement that several people … offered was, ‘They don’t bother me,’ ” writes Fennell. “Both women and men mentioned disliking the smell, taste, feeling, inconvenience, and sense of wastefulness of condoms.” Fennell drew the title of her paper from something a woman named Millie said, “It’s not the same feeling, it’s not the same closeness. It doesn’t feel as good. And isn’t that the point?”