The movie itself is dull in my opinion, and I don't mean that in a "old movies are lame" kinda way. I remember renting it and being bored out of my skull. I don't even remember what the plot was.
The only reason it exists is to be one of the best car chases ever.
Much of the credit for the chase should also go to stuntman and stunt coordinator Bill Hickman who also played the driver of the Charger (and actually drove it). He was also responsible for the chase scenes in The French Connection and The Seven-Ups.
Both the movie itself and its famous car chase were crushingly disappointing to me. Sure that chase was - and is - impressive from a technical standpoint, but all I ultimately saw was a car following another car.
It may be that I grew up watching silent movies. Harold Lloyd routinely did better chases for shits and giggles. Here, have a clip from Speedy (1928).
I think the heavy traffic helps considerably. It doesn't feel as staged.
The movie really didn't age well. I watched it, once, and was almost thoroughly bored by it. I can only recommend it if you want to scratch it off your "history of cinema" checklist and see THE famous car chase scene.
But if you just want to see a good movie with Steve McQueen, i'd recommend watching The Great Escape or Papillon again.