I've watched many of the episodes and I've found it to be very interesting and well worth watching. If you are a race fan and especially ones who grew up going to your local bullrings (either dirt or asphalt), you will probably enjoy these episodes. Lots of old racing history.
Definitely a good watch. Watched season 1 when it came out and just watched episode 1 of season 2 yesterday. (Daytona Beach and road course) Living only 25 miles from Daytona, I still learned new things about the course. (Always thought the original course was up in Daytona, but it was actually a few miles south down by Ponce Inlet.) Good stuff!!