If track has an effect it has a big effect. Take this example from Daily Racing Form's "Winning Techniques"...

"Some horses just love certain racetracks and aren't nearly as successful elsewhere. A great example is Lemon Drop Kid, who won the Futurity at Belmont as a 2-year-old but never threatened in subsequent stakes races in Kentucky. When he returned home to Belmont he ran a huge race and won the Belmont Stakes at 29-1! Lemon Drop Kid was a horse for the course. He loved Belmont Park. Daily Racing Form provides crucial data in the career box...If you see a horse who shows a particularly strong record at today's track, take note because he may be a horse for the course."

There are some courses that are definitely different; some tight and some with long, sweeping corners. In general I don't think there's that much of a difference -- but there are some out there that notice it.