The squeak is a good point, but the Rotos are not completely flat, and I can make them squeak a bit. And I have not found any way to make the pick attack sound like that on any kind of rounds. It's possible that they are something else similar to Rotos that are in the territory between standard flats and rounds, but the sound of the pick attack I'm getting with the Rotos is amazingly close, even without any compression or involved EQ. I would still be curious to know the exact setup in the clip, but I don't think it would make me change anything at this point because I love the sound I'm getting from these strings.