I finally got me copy today. I've only been able to skim most of it and read parts of selected sections. So with that limited amount of knowledge, here are my initial impressions:
Finally, a comprehensive modern rulebook. They didn't give you a starter kit and force you to wait 6-12 months for supplements to be release in order to fill in major gaps (like almost every other RPG I've ever bought does...).
The gear section looks like it will be just as useful for creating future tech as it is for creating spy-tech.
The character classes are first rate. Obviously, I haven't had a chance to take it for a test drive so I don't know what archetypes I can't create, but every example on the short list I ran through my head could be represented by either a core class or a multi-class combination. As a GM, I still may find the d20 Modern classes easier for developing character concepts, but I think Spycraft will be much easier for players. The NPC creation rules may overcome this suspicion, however and make Spycraft the clear winner.
The campaign section that provides rules/guidelines that allow you to tailor the campaign to your style of play is brilliant. I can't believe I've had to play RPGs for 20 years before seeing this concept executed so well!
If there's a book that proves that d20 can exist beyond it's D&D roots, this is it.
Finally, a cool way to handle computer hacking and interrogations. That it also handles seductions is just inch-thick icing.
And here's the weird one... And maybe there's nothing to it because I can't really nail down why I had this feeling, but as I looked through the book I kept thinking that if Alternity had been converted to d20 - this is what it would (or at least should) have looked like. I saw flashes of Alternity in the skill system, the flexibility of the rules, hell even the layout of the tables - although with all of them turned up to 11. It may be all in my head, but it was a much stronger feel than I received reading d20 Modern (which I also liked).
Can't wait to dive into this monster. Damn, but it looks like it's going to be everything I hoped for.
Now I just have to wait for my 2nd copy to get here! (No way I'm sharing with my players in-game.)
Azgulor