I love this product. It's funny and inspiring.
The weapons could have been presented in a neater way, like in a table or something, but I understand that it's easier to cut and paste the text this way so it's probably for the best.
Some annoying repetition of information when several weapons have the same effect, but again, that simplifies cutting and pasting and reduces the amount of time spent searching for the effect.
It's supposed to be compatible with D20 Modern, but I'm not so sure. It breaks the standard rules for firearms all the time (all firearms do 2 dice of damage, have a threat range of 20 and causes double damage on a crit in D20 Modern, but in this book you will find weapons dealing anything between one to 15 dice of damage, cause criticals with x3 or x4 damage, and with threat ranges from 16-20). This means we have to guess how to use some of the feats like "double tap" or "burst fire" with these weapons. Why is burst fire less efficient with a super-advanced firearm than with our normal kind? (A weapon causing 2d10 fired on burst setting gets a 100% increase to damage, a weapon causing 5d10 only gets a 40% increase?)
I suppose the rules are "broken" in order to provide more of a difference for the super-advanced weapons to shine, but it's still something which could have been taken into consideration by the author.
[5 of 5 Stars!]