PG-13 is def higher quality...always. Jk, that doesn't even make sense. It doesn't always matter. I mean movies rated NR or G or PG can be good. In general though I'd say I usually like things rated R better than PG 13 because they are less censored, or maybe I should say they are less often kid or family movies. But really a movie's rating doesn't always, by far, say anything about how good it is.
I'm going w/ PG-13. Movies like Thor, Captin America, Avengers, and Snitch were grand quality at PG-13 just to name a key some. Movies are more creative when they don't resort to nudity or overkill on bad word language or over kill on blood and gore.
But, movies are often less real when they censor out those commonalities of life that actually do happen in the adult and even children's world. Take the documentary movie Bully - one of benefit for children under 17. The MPAA robots first rated it R because it said 'fuck' more that the couple of times. Enough ppl protested until they lowered it to PG-13, making it accessible to the very ppl who would benefit from the movie. The rating of movies is often a controversial decision that does not make real sense. You can say 'fuck' in a PG-13 movie once or twice but say the same word more often it becomes R rated. WTF kind of logic is that if the kids know the word and can survive hearing it once but cannot hear it repeatedly as they do IRL with their peers?
neither. mpaa ratings are based on certain relatively arbitrary content factors, not on quality. a more answerable question would be "are one star movies or four star movies better?" although that's kind of a dumb question, even considering the fact that movie critics often give low ratings to great movies and high ratings to garbage.
I always though that an R rated film was rated so if there were high levels of sex scenes etc. or the abuse of women and children or just over the top violence. I didn't think swearing really came into it.
