Personally I really like Mosport, but I believe these training sessions are useful regardless of location.
I would pick whatever is most convenient for you for this course. After all, its about what they are teaching you rather than the track itself.
Get to know your car a little more, then hit some fun tracks to improve your skills in the spring/summer.
2011 Alpine White BMW E92 M3 | 2009 Jerez Black BMW E92 M3 | 2007 BMW E92 Coupe | 2005 350Z Grand Touring Roadster | 2002 RSX Type-S | 1977 Mustang Cobra II |