They are all bad - no argument from me. I don't use any herbicide on my property. None. I rather my family run, walk, sit, dig, and play in a yard full of weeds than a chemical wasteland. The amazing thing about both weeds and grass is that they are both green. And they both can be mowed or cut down.
That said, glyphosate (round up) is a known carcinogen, the active ingredients in Spectracide aren't classified as such (afaik)... yet.