I only really have four major complaints with Agito:
1. Having the universe constantly **** on Ryou is taken to an unnecessary extreme. Yes, I understand the Job metaphor, but there are points in the series where I seriously wonder why the man hasn't slit his wrists yet. It just feels unnecessarily forced, and having his only reward at the end of the series be a GODDAMN PUPPY (which probably has rabies and will die within a week, knowing his luck) doesn't really make up for it all.
2. The rather anti-climactic way in which his form changes are introduced. Obviously, I'm not talking about Burning Form, that was very well done. I also really enjoyed Trinity form's introduction by having it be used when his memory returns. But Storm and Flame just came out of nowhere with no fanfare or explanation. It was just "Hey, I can pull weapons out of my belly now. No real reason why, I just can". After the brilliant buildup and execution of form changes in Kuuga (especially with the Rising forms), that just doesn't cut it.
3. Shouichi was not that interesting of a character for most of the series. Sure, the mystery surrounding him was great, and they did a great job of making you really want to know about his past, but as long as he was an amnesiac, he really wasn't all that interesting to watch on his own. He really just felt like Godai without all of his subtlety and humanity. Admittedly, the boy was legitimately brain damaged, but he was just a little TOO simple, even with that taken into account. I significantly preferred him as a character when his memories returned.
4. Kino's medical "practices". Admittedly, this was probably due to the fact I watched the series with a Vet-Med student, but seriously, no doctor should be able to get away with the **** he did, especially performing TWO SURGERIES AT THE SAME TIME WITHOUT CHANGING GLOVES OR WASHING HIS HANDS.
Other than those issues, it's a great series. It's no Kuuga, but really, what is?
Oh, and Ozawa was amazing.