One thing I felt throughout the movie was that Lin and Morgan clearly intended this to be the final part in the series, what with all the throwbacks to the earlier entries in the series and the ending coming full circle with the family at Dom's place. I suddenly wasn't surprised anymore that Lin opted not to return for part 7 because this was his farewell to the series.
Another thing I noted was that for a series that features a lot of objectified women (no complaining there btw), all the female leads tend to be strong characters. They poke fun at the men, hold their ground and aren't useless damsels in distress. Hell, in the end Han's girl Gisele was the ultimate ride or die chick, you know in every other movie she would've just lost her grip and fall to death but in this she actually let go so she could shoot the motherfukker coming for her man. That's my girl.