This supplement is packed with good stuff. Many new customization options enable new kinds of mecha builds (or help builds that didn't quite work too well with just the corebook). Personal highlights include Versatile Model (for the typical protagonist Gundam that uses melee and ranged weapons roughly in equal measures), Remote weapons (for if you like your Funnels to work more like they do in the shows instead of how they work in SRW or SD Gundam G Generation), and new fun combination options (Invincible Super Combination for units that are much better combined than they are as individual units, and Universal Component for units that can "combine" with - or rather dock onto - any ally unit).
The new rules systems are also a welcome addition. The Element System can help with certain niche mecha properties (like the Lord of Elemental spin-off of SRW), but are also useful to reskin this into a mon game.
Rules for Faction Management further add mechanical crunch to the players' mecha combat antics, while Hardcore Difficulty offers options for more long-lasting consequences and unexpected circumstances.
The book closes with a bestiary of challenging opponents, plus a number of scenarios to use them (like a classic Asteroid/Colony Drop scenario).
[5 of 5 Stars!]