I don't think there's been a comparison in a magazine but I know a few guys who have used both. They both perform just as well as they do the same thing. BUT, I think the Novak is easier to use. I have a Rayspeed and using the little screws can be a little hassle if you're tight on pit space i.e. at a big race, or if you're in a hurry. The Novak you just drop the pack in and hit the button. The adjustable cutoff is nice if you need it but I drop mine to .9 and that's where the Rayspeed is set anyways so it dosent matter. And the Novak just looks cool
Performance wise though, I think they're equal.