Pretty much decided to pick up an F2 Speedster GTS. Want a slalomish carving board for playing around on, making tight turns, steep-narrow-bumpy-crowded slopes, (here out west) etc. I'm vascillating on the length, 166 (9.8m SCR) or 163 (9.5m SCR). Been riding a Burton Ultra Prime 168 that I do OK on. Intermediate level. Have a Coiler 172AM (12m SCR) on order for more general riding. I'm 5'10 170-175 lbs. Any advice?