I'm tempted to give this 5-stars just for how well MOST of it holds up 40yrs later. This is better written than a lot of modern books. It also features interesting characters with complex relationships, not a bunch who all love each other deeply. Included is also a HUGE crossover with the Avengers that might be one of the original Marvel 'Events'. Even being from the early 70s, it is a pretty decent story.
Doctor Strange, Namor and Hulk form the backbone of this "non-team". Not always in agreement, nor even friendly with each other, this is a precursor to the team books where they are dysfunctional, except mostly, the Defenders rise above and get it done. Add in the Silver Surfer, and you have maybe the most powerful 4-man team ever. This would be a great movie, this team of 4. The writers also realize Hulk cannot be the front and centre all the time, and Namor isn't a team guy, so we've got a rotating cast, also adding Valkryie, Hawkeye, and by the end, Nighthawk (ya, who?). We also see Black Knight, The Avengers (Cap, Iron Man, Thor, Vision, Scarlet Witch, Black Panther, Swordsman (hahaha), and Mantis (who?)). We also see The FF, SHIELD (Fury and Dugan), as well as Spidey, Ghost Rider (both in tiny bits) and more. Loki and Dormammu are the major baddies.
I didn't expect to enjoy this as much more than a Marvel history lesson, but I loved mostly all of this.
I also see that there's a major plot line that is picked up again in Matt Fraction's new Defenders book (Also with Strange and Surfer) that made no sense at the time, but having read the old stories, I get it now.
I would recommend this to people looking for a change from all the modern gritty reboot shit, who want something a little more fun, yet not totally disposable. I only wish it were in colour!