Marshall, at first glance (or in my eyes):
Pros:
Mid Bab, d8 HD, 2 good saves, and the ability to use any Martial weapon, shield (but tower), and armor make it an adequate front line fighter (not the best, mind, but adequate). Auras are activated by a swift action (handy). Diplomacy on a Cha-based class, including free Skill focus (Diplomacy) and an aura adding Cha twice to those checks is nifty. Can grant move actions (which is very useful on a group of Melee classes). Free Skill Focus also means that Exemplar builds are plausible, especially depending on the Auras chosen. Intimidate is a class skill and it's a Cha-based class, although not as good as being able to do it swiftly. Circumstance bonuses on things other than skills are handy.
Cons:
Outranked by Clerics (of course), but also by Bards (Basically auras with caster levels), Factotums (get int/level to certain skills per encounter), and most ToB classes (White Raven does it better). Has no way of swapping out useless auras. Very little support in outside books. Approximately 5 dead levels (including levels where only 1 aura is gained) (6, 10, 11, 13, and 18). Low number of Auras known if multiclassing. Auras are somewhat restricted (60', must hear/understand, int above 3 (problems occur with animals/mindless undead, etc.), and is canceled if she is dazed, unconscious, stunned, paralyzed, or otherwise unable to be heard or understood by his allies.) Circumstance bonuses on skills are common, and much higher than what you can probably give.