That'd be why. Most of the 2nd party stuff isn't well referenced. Dragon Mag makes a horrible name for it, and Dragonlance I can't say helps, only they DL's most powerful stuff rolls out of the WotC's book (the campaign setting, reserves of strength/dragonspawn/etc).
KoK on the other hand. I never made it past the first book. Class wise nothing to major to be found, Spellsinger is a Sorcerer with Eschew Material Components and ignores Somatic Components but adds verbal to everything meaning it ignores Arcane Spell Failure chance. So I was already set to expect this book to hand out stuff far beyond what ever D&D Splat gives. But like anything, it's not the Classes or PrCs that take my first interest, but items, Feats, and Spells, in that order.
Items
KoK has lots of Alchemical stuff and herbs, woot. Nothing too powerful form what I recall, just shark repellent and save-less instant coma in a bottle. Oh boy, I hope the magical side has cool stuff. Just gotta read past the slave section and these arrows that always remove Dex-to-AC...
There is an armor that instantly cures you when you drop below 0HP but don't die. Unlimited use and I recall thinking it's pretty cheap for low level use. There is also a cheap casts Greater Dispel Magic each time you hit weapon. Then a +2 unnamed to Dex potion, some +1 Save DCs rings, that +! Comp Ioun Stone in 2k ring form, a spiffy +2 all Knowledge Skills ring, and Pelor knows what else.
Feats
There is a chain in there I make into jpegs. Eyes of Fury, once-per-round Free Action Gaze attack that shakens opponents. Fearsome Appearance requires it and adds a Will Save or any opponent cannot take an AoO against you. Commanding Presence tops this chain off with a none-Fear based infinite Free Action and Saving doesn't render you immune makes people Flee unless they have no other option. DCs are 10+ChaMod but who cares, you can make a Paladin crap his pants.
Oh, KoK is the source of Irresistible Spell, which is a +4 Metamagic that denies your chance to Save, I think it got updated to +10 Save DCs. But more importantly you can pick up a Feat to trade Turn Undead uses into ungodly effects. Like Saveless Confusion, Cone of Saveless Shaken, Cone of Web, deal WisMod Negative Levels to a target, and who knows what else.
Spells
I skipped it. I'm sure it's loaded with some overpowered content ripe for picking. KoK, like Dragon, was out to make a bad name for 2nd party material.