If anything, when I saw those ads, it was confirmation of all of the evils of HFCS. If HFCS weren't bad for you, they wouldn't need to advertise, right? That was my thought process anyway. But I went out and did research to see how much bullshit they were spewing.
Every scientific study has shown that HFCS is pretty much indistinguishable from sugar. And now major news outlets are picking up the story.
This isn't to say that HFCS isn't something to avoid. Empty calories aren't great for you, so someone who goes out of their way to cut HFCS is probably eating a healthier diet than one who isn't. And the real danger from HFCS isn't some chemical factory horror story about how it screws up your body, but the fact that it's used in everything. As the ads point out, HFCS is fine in "moderation", but it's almost impossible to eat it in moderation.
So, the conclusion: avoid HFCS and sugars because they're empty calories, not because you've heard some weird things about how your body breaks down HFCS.