Voadam said:
A 1st level MA will have a poorer AC than a fighter, one less feat, and 2 less hit points.
At higher levels the fighter still outpaces the MA on feats, hit points and AC.
The MA makes a slightly better unarmored and/or unarmed warrior than a fighter does, but I think that is the point of the class.
I hear you.
Fighter advantages: 2 hp, 1 feat, can wear armor
MA advantages: 8 skill points, better skills, +2 Reflex save, WIS bonus to AC, +1 AC
+2 reflex save is better than 2 hp, but let's call it even;
WIS bonus (+1) to AC is *far* better than 1 feat, but let's call it even;
8 skill points and better skills is roughly equal to ability to wear armor.
Assuming a 1st level fighter can afford scale armor, the WIS bonus (say +3) and +1 AC of the martial artist gives them the same AC, but doesn't have to pay anything for it and has faster movement.
Personally, and in the games I'm involved in, I believe the MA is far better. Using the above formulae, I suppose you could argue they are balanced at 1st level.
At 10th level, additional advantages:
Fighter: 9 hit points
MA: 18 skills, +2 more Reflex save, +2 AC bonus, lots of cool abilities that are worth more than feats (uncanny dodge, huge jump/tumble bonuses), more variety of feats to choose from than fighters
Assuming you can buy magic in your campaign, all this time the fighter will be investing more money in armor while the MA invests more money in bracers of armor, so that they will have roughly equivalent ACs. Also, the MA can buff his DEX or WIS to improve AC, but the fighter can often do neither (max DEX penalty). So, not only are MA cooler than fighters, they are also better than fighters.
As for a MA is "slightly" better than a fighter when unarmed and/or unarmored, are you sure you want to say "slightly"?
Disclaimer: I should mention that I don't like monks (an arguably balanced class in the core rules) because I think they are too powerful for someone in no armor with no weapons. So, undoubtedly a person who believes that monks are not powerful enough could argue with me for quite some time and neither of us would budge in our opinions.