The pacing of the first few story lines of the Ultimate Fantastic Four was genius. Not too fast, not too slow - heaps of character development with only a few villains introduced. The dialogue was snappy and the plots made sense - it felt like reading a good movie. The re-introduction of traditional Marvel elements (Doctor Doom, Mole Man, Annihilus) was done smoothly, with a great attention to detail.
Then... I don't know, someone must have dropped speed in the water cooler again.
The origin story - for one that has been retold a thousand times - is done in a meticulously rendered fashion. Brian Michael Bendis is doing a teenage origin story and Warren Ellis gets to crack out some science villains - two of the A-list doing exactly what they do best.
The Fantastic Four also feels more natural when the heroes are kids. The sense of wonder and discovery - they are, essentially, Marvel's finest science heroes - is a more organic fit. The classic story of coming of age in both traditional and non-traditional (e.g. 'moving things with their minds') adolescent fashions. With their 'genius' intellects, however, the reader was fortunately spared the bulk of the 'zits and all' retelling (Thing-pimples, yeek).
Then, overnight, Ultimate Fantastic Four suddenly came down with sequel syndrome: Superpowers were suddenly taken for granted, team existential melodrama was mysteriously raised... and settled... in the course of a single issue. Plus the predictable chestnut of multiple villains for every storyline.
I wound up quitting after the Frightful trade paperback. The Doctor Doom storyline in that arc was a terrific idea, yet it was introduced and resolved in a matter of pages when it should have taken months. Zombie alter egos, Lovecraftian elder thingies, mind swaps and fatal illnesses, all neatly resolved in one 42 minute time slot! Just another week at the Marvel methlabs.
Although I'm occasionally tempted to resume, I don't see myself risking further disappointment. Another immaculately paced title has been run into the ground by needless adrenalin - trying to give us everything we 'want', all at the same time. This series started out with flair, but wound up far short of fantastic.