I had read the story of Jim White and the McFarland cross country team long before the movie came out. I was glad to see it made into a feature film, but Disney's heavy hands keep it from being fully satisfying.
Most of the actors playing larger roles acquit themselves well. Yes, Kevin Costner is his overly familiar world-weary self, but there's always a certain charm in seeing him inhabit that role. Many of the young men portraying McFarland's runners are both charming and believable, and some of the quirky townspeople (such as the mother of three runners and the owner of the local variety store) add nice depth to the story.
In addition, the scenery is interesting, from the running trails to the fields where the McFarland runners pick crops.
One real turnoff was when, repeatedly, opposing runners were shown talking smack before the start of races, and opposing coaches made snarky comments about the McFarland team. I've coached youth sports for many years and am accustomed to seeing much better sportsmanship than that. The movie makers apparently needed to set up cartoonish villains so that the audience would root even harder for the good guys.
Another clunker came at the first race, the "Palo Alto Invitational." The race director was surprised when McFarland showed up - but if it was an "invitational," then either they'd been invited (so he shouldn't have been surprised) or they hadn't been (in which case they had no business going to the race).
This was a generally pleasant two hours, and it was good to know that the basic heartwarming events took place in real life. Could have been better (or at least less bad in some parts), but it was OK. I recommend you find the story "Running for Their Lives" by Gary Smith, the captivating real-life tale of Jim White and McFarland (told as only the brilliant Smith could).
