Being a huge of mecha and kaiju anime and video games, I was greatly pleased to see Guillermo Del Toro taking a chance in such film, seeing as I'm big fan of him too.
Visuals are great, fights exhilarating and visceral, designs are excellent, and I even got a few laughs too.
While the film is a great big pile of fun, I can't help but feel that this is one of his weaker films. I'm aware it's essentially a "live action anime" with the appropriate tropes and cliches to match, serving as homage, but it's a bit weaker in some areas for it. Or at least, the film would of been better if it didn't take itself so seriously or subverting some of tropes. These problems bothered me most in the characterization, particularly the lead, his rival, and the female lead; the anime tropes are played so straight here, it just feels tired and ended up being the most uninteresting part.
The worst part of the film, is for whatever reason, the head of the Jaegar project decides to put a talented, but obviously traumatized, rookie into a Jaegar, triggering her via neural handshake, nearly ruining everything. This just seems really off in a military setting and done solely for drama.
Characterization aside, the best parts of the film are obviously the Kaiju fights and the performances of Ron Perlman and Idris Elba. I went into this film wanting to see the sheer spectacle of giant robots with great names fighting kaiju, and it delivered. If you can over the iffy characterization and cliches played so straight in a film that takes its self seriously, go see it.
edit: But also, what disappointed me above all else was the limited screentime of the other jaegers. :(