This past weekend I did the pacesetting on the Volkl RaceTiger Speedwall GS - 175 cm/ 17.5 m radius.
I set varying courses from fairly straight to very turny and the boards performed well. Can't think of any negatives. I still have to try the Elan GSX and the Rossi 9GS but at this point my favorite is next year's Atomic D2 Redster.
Unrelated: I've been searching for four years for a boot that I can use for both ski and snowboard racing. At the NASTAR Nationals each year I have to be in two places at once. The boot change makes me even later getting to the start. This weekend I experimented with the Dalbello Krypton Cross ID boot. It worked fine on skis and by loosening the top buckle and power strap I was able to get low enough to feel comfortable racing on my board (Sigi Grabner GS board 178 cm).