It's awesome. Some people have been complaining about certain talents or equipment, but for the most part, I don't see the big deal. Yes, Imperial Knights gets a single talent that's essentially Armored Defense + Improved Armored Defense. However, to get it, you'll have to belong to a select group of people, and you'll have to go your first 7 levels without it, unless you want to start focusing on Armors before you reach your prestige class. Also, as pointed out by Rodney Thompson in the latest Order 66 Podcast (featuring discussion of the Legacy CG with Rodney, Sterling Hershey, and Gary Astleford), you can only take five total talents from the Imperial Knight prestige class. Taking this one talent represents 20% of your total talents in the class. Compared to a Soldier, you can gain a total of 10 talents from the class, but have to spend 2 talents to get the same benefit... also 20% of your total allowed talents in the class. So, yeah, hardly gamebreaking at all. Of course, it's a shame that they named it Armor Mastery, as that's the name of a Soldier Talent, so that might need some clarification, heh. :p
*drools*