As the subject says, this series is intended to pay homage to the series that Shouji Sato probably enjoyed when he was younger. In fact the advertising for the series focuses on this aspect, with the quote "Love, Adventure, Danger... Everything I need to know about these things I learned from comics!" You have many of the old cliches, including an easily excitable gluttonous hero with a heart of gold, a stupidly powerful villain who's part of a bigger organization and has a sexy sidekick, and a post nuclear holocaust world. But as you'd expect, Shouji brings to the table all the stuff he's known for--ridiculously detailed art for weapons and vehicles, his distinctive character art, and of course, giant boobs and loads of fanservice. It makes for a kind of surreal experience, but it's definitely enjoyable if you approach it correctly.
The atmosphere of the series is quite a departure from his other series; unlike the mostly serious and extremely gory nature of Highschool of the Dead and Triage X, FFF is mostly lighthearted and doesn't have very graphic violence. There's some sexual content here, with a fair amount of implied sex that isn't actually shown, and that's one of the things that makes the series kind of surreal. For one thing, there's a character who tends to kill people by uh... having sex too hard, I guess, and there's some surprisingly dark humor related to sex that's actually quite funny.
The action scenes are thought out well and flow nicely, and the gags are actually pretty funny much of the time, unlike the mostly unfunny humor in HotD and TX. Despite the fact that this was published bimonthly, the pacing here is actually much better than either HotD or TX (which both suffer in this regard), with arcs wrapping up quickly and the characters moving from one place to the next without too much dialogue to sidetrack the story.
Shouji Sato said that his editors let him write basically whatever he wanted for this series, and it shows. It's over-the-top and can be a little strange, but if you bear with it, then you should find a solid series with a lot of familiar ideas executed very well. The only real "flaw" I see in the series is its ending, which leaves quite a few loose ends open, but the author has said he wants to continue it, so who knows, it may just get a proper ending one day.