By coincidence I have THREE American customers about to use the Spider in such a way.
The first should be using it for the first time later this month. He is already the world record holder in his class and is aiming to substantially improve on the times he achieved using US products.
The second (who is also a world record holder in a number of classes), has also had us supply a DP system (as well as the Spider), because he's unsure how the Spider will be treated in some of the classes he races in. If they outlaw the Spider or handicap the car for using it, he'll switch to the DP system. He's also assured me he'll do accurate back to back testing to see which produces the best results - my money is on the Spider.
This customer should be racing in March, so not much longer to wait for some results of at least the DP system for sure.
The third customer has yet to be sent his systems but he's already used a Spider and recorded better results than a NOS big shot plate and we're now supplying him with a much higher flowing system.
2 of these are dry systems and use the Spider as a plenum system rather than a plate system, by inverting the Spider central section and feeding it from underneath the plenum.