Trailblazer aims to bring well thought out solutions to common game play problems for 3e games. It starts out by presenting the problems and a summary of what will be done. It presents a mathematical analysis of the game before presenting changes and then shows how things balance out after their changes.
The presentation is wonderful. The authors present insightful comments in context with rule changes to explain why certain changes were made.
I particularly like the attention to the classes. Each of the base classes in 3e have been reworked to fix commonly cited problems. Overall, I think the changes are progressive, yet steeped in tradition enough to not be radical.
Subtle changes to combat including combat manuevers similar to the ones presented in Pathfinder, action points similar to those presented in Unearthed Arcana, and cleaning up rules that often were speed bumps in actual play should be welcome to most, I would think.
Other notable changes are streamlining of adjudication of vision, skill consolidation, and much more.
Not to be forgotten are guidelines to help the GM in preparation for a session including static XP calculation for monsters, encounter budgeting, and an analysis of the Big Six Magic Items.
The rules are presented as a cohesive whole, yet they are modular enough much like Unearthed Arcana, to be cherry-picked and used as desired. I highly recommend this product as it is insightful. I wish this kind of analysis and options came in guides for game masters.
Overall, this product is well worth the price paid.