As said above: this is for either new players who are just starting out, or people who absolutely must own every BattleTech product ever made. It's literally a compilation from prior sources: there's no new text, and, for that matter, no effort to rationalize the timing of any given entry, so references to "recent events" on one 'Mech's entry may be ancient history for another one, which for a new player might lead to some confusion, especially as then the opening fluff is referring to an even farther-in-the-future period of BattleTech history.
The artistic style varies wildly based on what book it was taken from: the rough line sketches from the original TRO: 3025 sit alongside the clean well-inked drawings from TRO: 3050-Upgrade. It does omit all the Unseen (those classic 'Mechs whose original art was the subject of a rights dispute). Given that many of the Unseen 'Mechs have had revised artwork in either Project Phoenix or in the Combat Manuals series, I would have really liked if they had included those 'Mechs as well.
[3 of 5 Stars!]