Be interested to see how you make out. I bought 8lbs of 570 a few years ago and had good luck with it. My only 2 complaints were the long kernels feeding through the funnel and more than normal carbon fouling. This was in a 6.5 saum.
I was hoping 568 was going to be a 'SSC' of 570 but from what I've read 568 doesn't get quite as much velocity. Wouldn't be a deal breaker for me as long as I could find an accurate node with it.
Good luck and keep us posted