I think 60Hz would be fine for most people. In fact, that would probably make it more relevant for most people. Like I said though, if you're one of the few who has a 120Hz monitor, you might not find it sufficient. As far as overhead, they briefly mention a few things they have or are trying to work out, but I can't imagine they don't put the card in a seperate system from the one being benched, so no performance hit for the card/computer being tested. You just have to make sure the other system can keep up, essentially.