I was actually let down by this--not hard, it was still entertaining, but I never found myself really into either the characters, the story, the plot, or the monsters.
I've always thought there was two ways to do this kind of movie--either shadowy/scary/quasi-horror film, just a big Friday the Thirteen, or go 100% giant monsters and giant monsters punching each other in the mouth. I don't care if the latter is kind of stupid, it's just hilariously entertaining along the way. I thought the original Godzilla and, to a lesser extent, Cloverfield did the first one well, while a lot of the "classic"/stupid Godzilla films did the second one well, and Pacific Rim really knocked it out of the park for some unapologetic fun with enough "world-building" in terms of machines, settings, colors, monsters, themes, and visual allegories to keep it from being banal.
I think this one tried to do a little bit of both but didn't do either one particularly well. The "mystery" and the "payoff" moments loss some luster because (a) they already did one or two for MUTO even before Godzilla (b) we all know who/what Godzilla is at this point, there is no real mystery (c) there were so many false starts on the final reveal that, by the time it actually fully happened, it was more relief of frustration than triumph to finally see our hero. They weren't exactly clear on Godzilla's "status" in this thing either--is he the nihilistic embodiment of science gone awry and nuclear weapons, a larger allegory for pollution/global warming, or a literal folk hero and the personification of humanity's fighting spirit in 300' lizard form? I wasn't really sure besides the "nature's way of bringing balance" and "relic of an ancient ecosystem" and "feeds on radioactivity" hand-waving, which was weak even for this kind of movie. The big reveal in Hawaii was awesome, but, then, THEY IMMEDIATELY CUT AWAY FROM THE FIGHT. WHAT!?!
Pacific Rim had a monster and destruction in its *first scene,* and it was ~5 minutes until Gipsy was in its first robot v. monster fight. That is how you do this the "fun" way. Godzilla finally gave us that fight at the end, but it was so slow and drab looking, and dark, to boot, and rather short. I honestly enjoyed some of the classic rubber suit ones more, never-mind the raw artistry of Pacific Rim (and the increased human element of having the pilots in the machines themselves, making them an extension of the main characters, even if relatively thin ones).
So, yeah, I was hoping for more. Wasn't as suspenseful as it thought it was, never built much real tension, and the payoff needed to come in Hawaii before blowing us away in San Francisco. In the end it was just adequate with one fight too late, which was really the thing as a whole for me. It, for once, even if this was trying to be Jaws more than anything else with the suspense, waited too long and never developed its true main character/monster in any way because of it.
I'm not a hater, too--I love all those Toho films. To death. Pacific Rim, despite low expectations going in, quickly became a favorite and, to me, a spiritual successor to the "monster rumble" films of the 1970s. This one just didn't hit the line between 50s-style creature feature (i.e. the original GZ) and the former categories, and thus didn't do either particularly well. :/