I really enjoyed it. I was a huge fan of the comic book when i was growing up, and they took many of the best things from the different best versions of the team:
*Most of the ideas come from the classic Lee-Kirby run on the team in the 60s, especially the dynamics of the team bickering and teasing each other as a family, the futuristic look of Reed's machines, the cosmic part of the film in outer space, and Galactus's look, especially (even down to the weird boots). The plot of the movie was a mash-up of the famous "Galactus" trilogy (FF#48-50). It also relied on the classic plot device Lee would use in the late 60s where Reed would invent some new incredible device at the beginning of a multi-parter that would be eventually used to trap or defeat the supervillain the team was up against,
*It also stole ideas from the Gerry Conway-Rich Buckler run on the book in the early 70s, where a different supervillain (Annihilus) tried to awaken baby Franklin's incredible mutant powers to use for his own ends
*A lot also came from John Byrne's famous run on the book in the 1980s, when it became established that Sue was the moral center of the team as well as the most powerful. It was also during Byrne's run that H.E.R.B.I.E. the robot was used as Franklin's babysitter. And Byrne's Galactus three-parter also had the four fighting Galactus on the streets on Manhattan.
*Finally, much of the emphasis on the incredible worldwide celebrity of this team (and the planet's dependence on them in times of crisis) were taken from the great Kurt Busiek-Alex Ross miniseries "Marvels."
A few more things:
*despite what OP claims, Johnny WAS shown to be obsessed with girls (he originally is attracted to the Silver Surfer in the movie and the others tease him about it). The actor who played him is quite sexy with a great body, and is handsome without beung classically modelp-handsome like Chris Evans (which I actually thought was great).
*I liked having Ben being gentle-tempered and more mature most of the time, which is more like how Byrne portrayed him than Lee-Kirby did. I liked that they got a Jewish actor to play him (since it's canon now that he was raised in a Jewish household)
*Vanessa Kirby gave the best performance in the film as Sue, and really showed how strong she was. She and Pascal genuinely had chemistry together, but I liked that she also doubted him sometimes like she so frequently does in the comics (though she always comes back to trusting him).
*The real star of the film is the design of late 60s NYC--they make it look believably and inventively retro-futuristic.
*The space sequence was very much like the Lee-Kirby stories, but I thought it was the most boring part of the film. It just went on for too long.
