LightPhoenix's point is closer to my real point here, even though I'm sure he isn't endorsing my point of view. My apologies that I am not an effective enough communicator to get that across. 
Disregarding the obvious pointlessness of discussing this with people that seem only interested in the min/maxed abilities of a single class, I do actually have 1 real question and a couple little technical quibbles.
A fighter 12 gets +12 BAB, correct?
A centaur has a +7 attack bonus according to my MM. 4 of which come from it's 18 strength, correct?
Thus 12+3=15. Thats 3 attacks + 1 from speed wpn = 4 attacks. Or is this another oversight on my part?
There are a couple other minor quibbles:
A barded creature is only capable of carrying a rider and saddlebags. No other gear, regardless of carrying capacity. I assume this is being ignored because saddlebags of holding are on sale again in the Walmart magic shop for cheap at every village. Or maybe you have modified suits of barding that have a cargo platform instead of a saddle and still allow for full dex bonus. I heard they are 25% off clearance at Foley's.
The barded centaur has an astounding movement rate of 35. That's impressive! Definately makes up for being severly hampered in dungeons. The first time it falls into a 20' deep pit trap and is stuck for good because no one can pull it out, the human fighter will laugh all the way to the treasure room down the corridor. No, never mind, wizards always have extra levitate spells for that mem'ed, so it's not a real disadvantage.
I will conceed the mithril trick was pretty nice. But any DM that would allow this is over generous IMO. Those master armorors that can make such a suit of exotic full plate that allows for that kind of ease of movement, despite the terribly complicated ariticulation that would probably be needed between the human torso and horse torso are apparently growing on trees in most campaign worlds.
I guess the games I like to play in are much different than those of the people on this board. I was under the impression that just getting a suit of halfling full plate in a human city ought to be a little challenging and more expensive ...

Disregarding the obvious pointlessness of discussing this with people that seem only interested in the min/maxed abilities of a single class, I do actually have 1 real question and a couple little technical quibbles.
A fighter 12 gets +12 BAB, correct?
A centaur has a +7 attack bonus according to my MM. 4 of which come from it's 18 strength, correct?
Thus 12+3=15. Thats 3 attacks + 1 from speed wpn = 4 attacks. Or is this another oversight on my part?
There are a couple other minor quibbles:
A barded creature is only capable of carrying a rider and saddlebags. No other gear, regardless of carrying capacity. I assume this is being ignored because saddlebags of holding are on sale again in the Walmart magic shop for cheap at every village. Or maybe you have modified suits of barding that have a cargo platform instead of a saddle and still allow for full dex bonus. I heard they are 25% off clearance at Foley's.
The barded centaur has an astounding movement rate of 35. That's impressive! Definately makes up for being severly hampered in dungeons. The first time it falls into a 20' deep pit trap and is stuck for good because no one can pull it out, the human fighter will laugh all the way to the treasure room down the corridor. No, never mind, wizards always have extra levitate spells for that mem'ed, so it's not a real disadvantage.
I will conceed the mithril trick was pretty nice. But any DM that would allow this is over generous IMO. Those master armorors that can make such a suit of exotic full plate that allows for that kind of ease of movement, despite the terribly complicated ariticulation that would probably be needed between the human torso and horse torso are apparently growing on trees in most campaign worlds.
I guess the games I like to play in are much different than those of the people on this board. I was under the impression that just getting a suit of halfling full plate in a human city ought to be a little challenging and more expensive ...