A useful re-packaging of the d20Modern rules but with sufficient weaknesses that I can only give it 3 out of 5 stars.
d20Modern broke considerable ground back at the turn of the century, and follow-up supplements provide an all-encompassing modern work-up of what was basically seen as fantasy domain before that. Different sections of the book divided career progression (classes) into various genres. So, if you only planned to stick to mundane events, you didn't need to worry about arcane magic or psionics.
The core rulebook re-presents the d20Modern rules, in a non-sectioned fashion, so everything is there in one giant list of classes and progressions. Did I say everything? Well, that's the weak point. Only some of the classes available in the vast world of supplements are there, and there are some significant pieces of progressions missing. Moreover there is an unwelcome (to me) addition of future classes that should really be left to space/future rpg supplements. I would much rather have a vast array of progressions (talent trees, advance classes) from each of the basic Modern classes.