Thankfully, this version of Rebecca is only an hour long, and that's with commercial breaks. Joan Hackett isn't any less irritating than Joan Fontaine was in 1940, and even though James Mason is more likable than his predecessor, he doesn't save the movie because he has a much smaller part than the female lead.
Joan impulsively marries the mysterious James and when he brings her back to his mansion, she gets curious as to the reason behind his strange behavior. It sounds much more interesting than it actually is, no matter which version you watch. While Laurence Olivier was moody and hormonal, James Mason actually seems to have motivations behind his actions and dialogue. Still, Joan is rather silly, gullible, and spineless, and if you can't root for her, you're not going to like the movie. Try Jane Eyre instead.