Yeah, I've heard FFDP before and I gotta say, they don't personally do anything for me. Not quite as catchy, or shall we say "melodic" are the others you mention. Mark and I have similar modern rock tastes, though, and I know he favours them a bit.
I like Stone Sour and wonder why they don't appear to more people here. I guess it's just because no one really has heard them or is willing to give them a go? I only wonder because it's basically pure hard rock / metal they play, and the "modern" part is just a mixing of words.
I know a lot of people who are put off by the Slipknot connection ... which is a pity 'cause Stone Sour are actually very good ... like you say, more pure HR/metal than 'shouty blokes with more piercings than talent' ...