Tracks are different today. They just don't get as rough. Good/bad you decide. I raced the Unadilla track back in the 80's and it was tough. Holes everywhere. that uphill before Screw-U, now called the Wall was just unbelievably rough. Yesterday, it wasn't so rough. I think it is a combination of the bikes power and suspension that keeps the holes from developing in the straights as bad as they used to be. No doubt the bikes go faster today.
My brother raced yesterday at 45 years old ( yes the pro program-his goal is to be the oldest guy at a national one day) and my dad has been there for both of us. He agrees, it isn't like it once was with line selection and all. It is opened up and much faster. It is also wider.
A note on the tracks-Do you think the boy on the 85 CR 250 at Loretta Lynn's could have gone faster than Bailey did in 85 on 85 works stuff? I think so, so the riding has improved along with the tracks just plain being faster.
Just my 2 cents