I thought it could have been the easy best blockbuster of the summer (still in contention after one viewing) but it had two pretty glaring flaws that held it back a bit. But first, the good- the ensemble was absolutely excellent from top to bottom. Very, very impressed with Hunnam and the chick from Babel, and Elba, Day, and Perlman were great as expected. The score was fantastic. The direction and visual feel of the movie was great. The robot designs were awesome. The world building was top notch. The dialogue was crisp and fun. The environments and settings were great. It really nailed the sense of fun.
However, two things hurt it
1. The prologue needed to add at least five minutes. I never felt the scope of the kaiju taking over, the Jaegers fighting back, and the kaiju pushing humanity to the brink because the prologue was rushed. It felt like being dropped into the middle of the story.
2. Between the fact the that kaiju all looked the same and all the fights took place in the dark and around water/rain, the three main action scenes let me down.