I saw "Fast & Furious 6" the other day. I have no recollection if I saw versions 1-5. I was pretty tired at the movie and I slept thru a good quarter of it.
I liked the cast (Vin Diesel, the Rock and more) and the action was okay for a while, then got repetitive . Fun I guess but forgettable. They set up Fast and Furious 7 with a twist... stay for the credits.
I'm sure it will do well in the box office, just didn't work for me