I think that this class rocks.

Seriously. This class is pretty nice. It is the monk, only, you know... good.

I'm sorry if you disagree, but, IMO, the monk is pretty much trash. Anyone can whip on the monk. He can't hold his own in CR equivalent monsters.
At level 16, the monk now can hit stuff that has DR Big number/Adamantine. Yay. Now before you say that this applies to the brawler, go back and take a look at that weapon proficiency list. Spiked Gauntlets. I.E. Adamantine +5 ________ Spiked Gauntlets. Anyway, there 4 CR 16 monsters in the D20 SRD that I can find. Eh, ok. So, since a Core Class should be able to go 50/50 with a challenge of its own level, he should either be able to go 50/50 with all of them, or, flat out win against two, and lose hard to the other Two.

The Horned Devil has Regeneration Good and Silver, Flight, Summoning, and three chain attacks with a nasty stun. If the horned devil attacks first, the monk is toast.

The monk's best attack (unarmed attack) is pretty much worthless due to the Regeneration 10 vs Non good and silver attacks. With a generous 20 strength at level 16 for a class that almost defines MAD, you average 20 damage a round if EVERY ATTACK HITS. And versus his AC of 35 (39 if you are good), I'm sure you can imagine how likely that is. 9 rounds of standing there full attacking. If you are lucky, he will laugh himself to death.
A +5 silver, holy, keen Kama is a much better bet. But still, he can easily laugh at least three rounds of your attacks, and by then, you will have probably failed your save versus his Permastun.

Now, if your Brawler knows he is going to be fighting a horned devil, he should probably get 5 silver, returning, holy xxxxxxxxx, where xxxxxxx is a non-breakable object. The Horned Devil will last about two rounds of returning, holy chairs, or whatever. You got a decent chance of getting through to get tow rounds off on him, which might drop him. But it isnt 50%.

Verdict: Lose, sans rolls that will make people check your dice for shaving and such. Mr. Brawler has a shot, but odds are he's going down.

Number two: Planetar

Eh, its a Good Outsider, so most people won't end up fighting one, but still, this guy will make mincemeat out of a monk.

First, he can fly faster than you can run, so you probably won't get into melee unless he wants you to.
Second, Save or lose make non-casters sad. He has at least two if you rip him right out of the MM. Also, once per day, he can use waves of exhaustion, which make people who have to hit stuff for a living sad.
And Summon Monster IX, so he fly rings around you and laugh while you try to fight a Leonal. If you win, he can probably some and poke you to death. Or just use those nifty save or lose spells.

Verdict: Lose, flat out lose. To be fair though, the Brawler would also lose, so just keep that in mind.

Number Three: Nightwalker. Wow. Just take a look at this guy and tell me that he can't completely own a Monk. Again though, Mr. "Overpowered" Brawler loses too...

Verdict: Lose.

Number Four: Greater stone golem will hit on pretty much everything but a Nat one. With two attacks (Unless the monk is doing some Silly Spring Attacking) that averages to about 62 damage per round. Mr. Monk gets smacked down in 4 rounds, max. Mr. Monk on the other hand needs to hit about 25 times. And beat AC 27. If he decides to prolong the fight by spring attacking, he gets to live until hit 4 or 5 times.

On the other hand, the Brawler gets more attacks that hit, more damaging attacks since he can use the +5 __________ gauntlets and rage, more HP, and has DR to take some of the hurt off of the swings.

In short, I'd give him 75% chance of coming out on top.

Verdict: Monk go splat, but Brawler shines.

Huh. At the end of this, the monk lost all of his fights, while the Brawler came out with one iffy, two loss, and one probable win.

It seems that the Brawler is more balanced against the core monsters than the monk...

So, people are right. The Brawler is better than a Monk. And so is a Fighter, Rogue, Cleric, Barbarian, etc. I think that this should replace the monk. It may not have been intended to, but I think that this should replace the monk.

Imo, you could bump him back up to D12 hit dice, just to be safe. After all, his armor is gonna be kinda low for a front line fighter.

*Disclaimer* This is my opinion. Of course, I think it's right, though, but feel free to talk about how a monk could win.