Imo the 7-port is best suited for the buggy on large tracks, 3-port on short tracks for buggy and the 5-port for truggy on both short and large tracks. Matts performance this weekend really shows how well the new GX line compares with all other mills out there. I personally think 2010 will be the year of GO TECH!!!! Were going to open ALOT of eyes this year coming up.